Publications by year
In Press
Derex M, Bonnefon J-F, Boyd R, Mesoudi AA (In Press). Causal understanding is not necessary for the improvement of culturally evolving technology.
Nature Human BehaviourAbstract:
Causal understanding is not necessary for the improvement of culturally evolving technology
Highly-optimized tools are common in traditional populations. Bows and arrows, dogsleds, clothing, houses, and kayaks are just a few examples of the complex, exquisitely designed tools that humans produced and used to colonize new, demanding environments. Because there is much evidence that humans’ cognitive abilities are unparalleled, many believe that such technologies resulted from our superior causal reasoning abilities alone. However, others have stressed that the high dimensionality of human technologies make them very hard to understand causally. Instead, they argue that optimized technologies emerge through the selective retention of small improvements across generations without requiring explicit understanding of how these technologies work. Here, we find experimental support for the latter view by showing that a physical artifact becomes progressively optimized across generations of social learners in the absence of explicit causal understanding. Moreover, we show that the transmission of causal models across generations has no noticeable effect on the pace of cultural accumulation. The reason is that participants do not spontaneously create multidimensional causal theories but instead mainly produce simplistic models related to a specifically salient dimension. Finally, we show that the transmission of these inaccurate theories 1) constrains exploration in subsequent generations of learners and 2) has negative downstream effects on their understanding. These results indicate that highly optimized technologies need not result from enhanced causal reasoning but instead can emerge from the accumulation of many small improvements made across generations linked by cultural transmission, and demand a focus on the cultural dynamics underlying technological change as well as individual cognition.
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Mesoudi A (In Press). Migration, acculturation, and the maintenance of between-group cultural variation.
Abstract:
Migration, acculturation, and the maintenance of between-group cultural variation
AbstractHow do migration and acculturation (i.e. psychological or behavioral change resulting from migration) affect within- and between-group cultural variation? Here I answer this question by drawing analogies between genetic and cultural evolution. Population genetic models show that migration rapidly breaks down between-group genetic structure. In cultural evolution, however, migrants or their descendants can acculturate to local behaviors via social learning processes such as conformity, potentially preventing migration from eliminating between-group cultural variation. An analysis of the empirical literature on migration suggests that acculturation is common, with second and subsequent migrant generations shifting, sometimes substantially, towards the cultural values of the adopted society. Yet there is little understanding of the individual-level dynamics that underlie these population-level shifts. To explore this formally, I present models quantifying the effect of migration and acculturation on between-group cultural variation, for both neutral and costly cooperative traits. In the models, between-group cultural variation, measured using F statistics, is eliminated by migration and maintained by conformist acculturation. The extent of acculturation is determined by the strength of conformist bias and the number of demonstrators from whom individuals learn. Acculturation is countered by assortation, the tendency for individuals to preferentially interact with culturally-similar others. Unlike neutral traits, cooperative traits can additionally be maintained by payoff-biased social learning, but only in the presence of strong sanctioning institutions. Overall, the models show that surprisingly little conformist acculturation is required to maintain realistic amounts of between-group cultural diversity. While these models provide insight into the potential dynamics of acculturation and migration in cultural evolution, they also highlight the need for more empirical research into the individual-level learning biases that underlie migrant acculturation.
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2019
Brand CO, Mesoudi A (2019). Prestige and dominance-based hierarchies exist in naturally occurring human groups, but are unrelated to task-specific knowledge.
ROYAL SOCIETY OPEN SCIENCE,
6(5).
Author URL.
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Jiménez ÁV, Mesoudi A (2019). Prestige-biased social learning: current evidence and outstanding questions.
Palgrave Communications,
5(1).
Abstract:
Prestige-biased social learning: current evidence and outstanding questions
© 2019, the Author(s). Cultural evolution theory posits that a major factor in human ecological success is our high-fidelity and selective social learning, which permits the accumulation of adaptive knowledge and skills over successive generations. One way to acquire adaptive social information is by preferentially copying competent individuals within a valuable domain (success bias). However, competence within a domain is often difficult or impossible to directly assess. Almost 20 years ago, Henrich and Gil-White (H&GW) suggested that people use indirect cues of success (e.g. differential levels of attention paid to models by other social learners) as adaptive short-cuts to select models from whom to learn. They called this use of indirect markers of success prestige bias. In this review, we re-visit H&GW’s proposal, examining the evidence amassed since for the adaptiveness and use of prestige bias in humans. First, we briefly outline H&GW’s theory. Second, we analyse whether prestige is associated with competence within valuable domains, which is a crucial assumption underlying the adaptiveness of prestige bias. Third, we discuss prestige cues that people use to infer success (e.g. the amount of voluntary deference and attention received by models). Fourth, we examine the evidence for and against the use of prestige bias in human adults and children. Finally, we point out limitations in the current literature and present new avenues for research on prestige bias.
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2018
Mesoudi A (2018). Migration, acculturation, and the maintenance of between-group cultural variation.
PLoS One,
13(10).
Abstract:
Migration, acculturation, and the maintenance of between-group cultural variation.
How do migration and acculturation (i.e. psychological or behavioral change resulting from migration) affect within- and between-group cultural variation? Here I address this question by drawing analogies between genetic and cultural evolution. Population genetic models show that migration rapidly breaks down between-group genetic structure. In cultural evolution, however, migrants or their descendants can acculturate to local behaviors via social learning processes such as conformity, potentially preventing migration from eliminating between-group cultural variation. An analysis of the empirical literature on migration suggests that acculturation is common, with second and subsequent migrant generations shifting, sometimes substantially, towards the cultural values of the adopted society. Yet there is little understanding of the individual-level dynamics that underlie these population-level shifts. To explore this formally, I present models quantifying the effect of migration and acculturation on between-group cultural variation, for both neutral and costly cooperative traits. In the models, between-group cultural variation, measured using F statistics, is eliminated by migration and maintained by conformist acculturation. The extent of acculturation is determined by the strength of conformist bias and the number of demonstrators from whom individuals learn. Acculturation is countered by assortation, the tendency for individuals to preferentially interact with culturally-similar others. Unlike neutral traits, cooperative traits can additionally be maintained by payoff-biased social learning, but only in the presence of strong sanctioning mechanisms (e.g. institutions). Overall, the models show that surprisingly little conformist acculturation is required to maintain realistic amounts of between-group cultural diversity. While these models provide insight into the potential dynamics of acculturation and migration in cultural evolution, they also highlight the need for more empirical research into the individual-level learning biases that underlie migrant acculturation.
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Author URL.
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Mesoudi AA, Thornton A (2018). What is cumulative cultural evolution?.
Proceedings of the Royal Society B: Biological Sciences Full text.
2017
Mesoudi A (2017). Cultural evolution: Subsistence and social learning. Nature Human Behaviour, 1(5).
Schillinger K, Mesoudi A, Lycett SJ (2017). Differences in Manufacturing Traditions and Assemblage-Level Patterns: the Origins of Cultural Differences in Archaeological Data.
Journal of Archaeological Method and Theory,
24(2), 640-658.
Abstract:
Differences in Manufacturing Traditions and Assemblage-Level Patterns: the Origins of Cultural Differences in Archaeological Data
© 2016, Springer Science+Business Media New York. A relationship between behavioral variability and artifactual variability is a founding principle of archaeology. However, this relationship is surprisingly not well studied empirically from an explicitly “microevolutionary” perspective. Here, we experimentally simulated artifactual variation in two populations of “artifact” manufacturers, involving only a single behavioral difference in terms of their “tradition” of manufacturing tool. We then statistically analyzed shape variation in the resultant artifacts. In many respects, patterned differences might not have been expected to emerge given the simple nature of the task, the fact that only a single behavioral variable differed in our two populations, and all participants copied the same target artifact. However, multivariate analyses identified significant differences between the two “assemblages.” These results have several implications for our understanding and theoretical conceptualization of the relationship between behavior and artifactual variability, including the analytical potency of conceiving of artifacts as the product of behavioral “recipes” comprised of individual “ingredient” behavioral properties. Indeed, quite trivial behavioral differences, in generating microevolutionarily potent variability, can thus have long-term consequences for artifactual changes measured over time and space. Moreover, measurable “cultural” differences in artifacts can emerge not necessarily only because of a strict “mental template” but as the result of subtle differences in behavioral ingredients that are socially learned at the community level.
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Magid K, Sarkol V, Mesoudi A (2017). Experimental priming of independent and interdependent activity does not affect culturally variable psychological processes.
Royal Society Open Science,
4(5), 161025-161025.
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Mesoudi A (2017). Pursuing Darwin's curious parallel: Prospects for a science of cultural evolution.
Proc Natl Acad Sci U S AAbstract:
Pursuing Darwin's curious parallel: Prospects for a science of cultural evolution.
In the past few decades, scholars from several disciplines have pursued the curious parallel noted by Darwin between the genetic evolution of species and the cultural evolution of beliefs, skills, knowledge, languages, institutions, and other forms of socially transmitted information. Here, I review current progress in the pursuit of an evolutionary science of culture that is grounded in both biological and evolutionary theory, but also treats culture as more than a proximate mechanism that is directly controlled by genes. Both genetic and cultural evolution can be described as systems of inherited variation that change over time in response to processes such as selection, migration, and drift. Appropriate differences between genetic and cultural change are taken seriously, such as the possibility in the latter of nonrandomly guided variation or transformation, blending inheritance, and one-to-many transmission. The foundation of cultural evolution was laid in the late 20th century with population-genetic style models of cultural microevolution, and the use of phylogenetic methods to reconstruct cultural macroevolution. Since then, there have been major efforts to understand the sociocognitive mechanisms underlying cumulative cultural evolution, the consequences of demography on cultural evolution, the empirical validity of assumed social learning biases, the relative role of transformative and selective processes, and the use of quantitative phylogenetic and multilevel selection models to understand past and present dynamics of society-level change. I conclude by highlighting the interdisciplinary challenges of studying cultural evolution, including its relation to the traditional social sciences and humanities.
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2016
Schillinger K, Mesoudi A, Lycett SJ (2016). Copying error, evolution, and phylogenetic signal in artifactual traditions: an experimental approach using "model artifacts".
Journal of Archaeological Science,
70, 23-34.
Abstract:
Copying error, evolution, and phylogenetic signal in artifactual traditions: an experimental approach using "model artifacts"
© 2016 Elsevier Ltd. Spatio-temporal patterns of artifactual variation are increasingly being studied via the explicit application of cultural evolutionary theory and methods. Such broad-scale (macroevolutionary) patterns are mediated, however, by a series of small-scale (microevolutionary) processes that occur at the level of individual artifacts, and individual artifact users and producers. Within experimental biology, "model organisms" have played a crucial role in understanding the role of fundamental microevolutionary processes, such as mutation and the inheritance of variation, in respect to macroevolutionary patterns. There has, however, been little equivalent laboratory work to better understand how microevolutionary processes influence macroevolutionary patterns in artifacts and their analysis. Here, we adopt a "model artifact" approach to experimentally study the issues of copy error (mutation) and resultant phylogenetic signal in artifact traditions. We used morphometric procedures to examine shape copying error rates in our "model artifacts." We first established experimentally that statistically different rates of copying error (mutation) could be induced when participants used two different types of shaping tool to produce copies of foam "artifacts." Using this as a baseline, we then tested whether these differing mutation rates led to differing phylogenetic signal and accuracy in two separate experimental transmission chains (lineages), involving participants copying the previous participant's artifact. The analysis demonstrated that phylogenetic reconstruction is more accurate in artifactual lineages where copying error is demonstrably lower. Such results demonstrate how fidelity of transmission impacts directly on the evolution of technological traditions and their empirical analysis. In particular, these results highlight that differing contexts of cultural transmission relating to fidelity might lead to differing patterns of resolution within reconstructed evolutionary sequences. Overall, these analyses demonstrate the importance of a "model artifact" approach in discussions of cultural evolution, equivalent in importance to the use of model organisms in evolutionary biology in order to better understand fundamental microevolutionary processes of direct relevance to macroevolutionary archaeological patterns.
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Mesoudi A (2016). Cultural Evolution: a Review of Theory, Findings and Controversies.
Evolutionary Biology,
43(4), 481-497.
Abstract:
Cultural Evolution: a Review of Theory, Findings and Controversies
© 2015, Springer Science+Business Media New York. The last two decades have seen an explosion in research analysing cultural change as a Darwinian evolutionary process. Here I provide an overview of the theory of cultural evolution, including its intellectual history, major theoretical tenets and methods, key findings, and prominent criticisms and controversies. ‘Culture’ is defined as socially transmitted information. Cultural evolution is the theory that this socially transmitted information evolves in the manner laid out by Darwin in the Origin of Species, i.e. it comprises a system of variation, differential fitness and inheritance. Cultural evolution is not, however, neo-Darwinian, in that many of the details of genetic evolution may not apply, such as particulate inheritance and random mutation. Following a brief history of this idea, I review theoretical and empirical studies of cultural microevolution, which entails both selection-like processes wherein some cultural variants are more likely to be acquired and transmitted than others, plus transformative processes that alter cultural information during transmission. I also review how phylogenetic methods have been used to reconstruct cultural macroevolution, including the evolution of languages, technology and social organisation. Finally, I discuss recent controversies and debates, including the extent to which culture is proximate or ultimate, the relative role of selective and transformative processes in cultural evolution, the basis of cumulative cultural evolution, the evolution of large-scale human cooperation, and whether social learning is learned or innate. I conclude by highlighting the value of using evolutionary methods to study culture for both the social and biological sciences.
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Whiten A, Caldwell CA, Mesoudi A (2016). Cultural diffusion in humans and other animals.
Current Opinion in Psychology,
8, 15-21.
Abstract:
Cultural diffusion in humans and other animals
© 2015 Elsevier Ltd. Recent years have seen an enormous expansion and progress in studies of the cultural diffusion processes through which behaviour patterns, ideas and artifacts are transmitted within and between generations of humans and other animals. The first of two main approaches focuses on identifying, tracing and understanding cultural diffusion as it naturally occurs, an essential foundation to any science of culture. This endeavor has been enriched in recent years by sophisticated statistical methods and surprising new discoveries particularly in humans, other primates and cetaceans. This work has been complemented by a growing corpus of powerful, purpose-designed cultural diffusion experiments with captive and natural populations that have facilitated the rigorous identification and analysis of cultural diffusion in species from insects to humans.
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Mesoudi A (2016). Cultural evolution: Integrating psychology, evolution and culture.
Current Opinion in Psychology,
7, 17-22.
Abstract:
Cultural evolution: Integrating psychology, evolution and culture
© 2015 Elsevier Ltd. Cultural evolution represents a body of theory and findings premised on the notions that, (i), human cultural change constitutes a Darwinian evolutionary process that shares key characteristics with (but is not identical in details to) genetic evolution; (ii), this second evolutionary process has been instrumental in our species' dramatic ecological success by allowing the rapid, open-ended generation and accumulation of technology, social institutions, knowledge systems and behavioural practices far beyond the complexity of other species' socially learned behaviour; and (iii), our psychology permits, and has been shaped by, this cultural evolutionary process, for example, through socio-cognitive mechanisms such as imitation, teaching and intentionality that support high-fidelity social learning, and biases governing from whom and what we learn.
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Ellis EC, Richerson PJ, Mesoudi A, Svenning J-C, Odling-Smee J, Burnside WR (2016). Evolving the human niche.
Proc Natl Acad Sci U S A,
113(31).
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Lycett SJ, Schillinger K, Eren MI, von Cramon-Taubadel N, Mesoudi A (2016). Factors affecting Acheulean handaxe variation: Experimental insights, microevolutionary processes, and macroevolutionary outcomes.
Quaternary International,
411, 386-401.
Abstract:
Factors affecting Acheulean handaxe variation: Experimental insights, microevolutionary processes, and macroevolutionary outcomes
© 2015 Elsevier Ltd and INQUA the “Acheulean” is comprised of individual knapping events undertaken by individual hominins. In other words, it is a particular component of hominin behavior that we draw out and amalgamate into a wider “pattern.” the resultant phenomenon (i.e. “the Acheulean”) is an entity that stretches over the space of three continents and spans a time period in excess of one million years. If such an exercise has any merit, it is because it provides a means of comparative (behavioral) analysis over these swathes of time and space. Comparative research can document, measure, and statistically assess temporo-spatial patterns of artifactual variation, and so test hypotheses regarding the character of that variation. However, it does not provide an independent means of examining some of the key phenomena which it is necessary to further understand in order to increase our comprehension of this archaeological legacy. Here, we review and synthesize recent experimental work that we have undertaken, which has specifically investigated some of the factors potentially responsible for the generation and constraint of variation within the Acheulean techno-complex. We examine issues of raw material, copying errors, and their relationship to mechanisms of social learning. Understanding these microevolutionary factors via experiments, we contend, is essential in order to reach a secure understanding of the macroscale phenomenon typically referred to as the “Acheulean.” Moreover, we outline how a “quantitative genetic” framework to these issues provides an essential means of linking these inherent micro- and macro-evolutionary factors into a coherent whole, while also simultaneously reconciling the potential influence of different sources of variation that are part of a temporally and geographically dispersed entity such as the Acheulean.
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Mesoudi A, Magid K, Hussain D (2016). How Do People Become W.E.I.R.D.? Migration Reveals the Cultural Transmission Mechanisms Underlying Variation in Psychological Processes.
PLoS One,
11(1).
Abstract:
How Do People Become W.E.I.R.D.? Migration Reveals the Cultural Transmission Mechanisms Underlying Variation in Psychological Processes.
Cultural psychologists have shown that people from Western, Educated, Industrialised, Rich, Democratic (WEIRD) countries often exhibit different psychological processing to people from less-WEIRD countries. The former exhibit more individualistic and less collectivistic social orientation, and more analytic and less holistic cognition, than non-Westerners. Yet the mechanisms responsible for maintaining this cultural variation are unclear. Immigration is an ideal 'natural experiment' for uncovering such mechanisms. We used a battery of psychological measures previously shown to vary cross-culturally to compare the social orientation and cognitive style of 286 residents of East London from three cultural backgrounds: (i) 1st-generation British Bangladeshi immigrants; (ii) 2nd-generation British Bangladeshis raised in the UK to Bangladeshi-raised parents; and (iii) non-migrants whose parents were born and raised in the UK. Model comparison revealed that individualism and dispositional attribution, typical of Western societies, are driven primarily by horizontal cultural transmission (e.g. via mass media), with parents and other family members having little or no effect, while collectivism, social closeness and situational attribution were driven by a mix of vertical/oblique cultural transmission (e.g. via family contact) and horizontal cultural transmission. These individual-level transmission dynamics can explain hitherto puzzling population-level phenomena, such as the partial acculturation of 2nd-generation immigrants on measures such as collectivism (due to the mix of vertical and horizontal cultural transmission), or the observation in several countries of increasing individualism (which is transmitted horizontally and therefore rapidly) despite little corresponding change in collectivism (which is transmitted partly vertically and therefore more slowly). Further consideration of cultural transmission mechanisms, in conjunction with the study of migrant communities and model comparison statistics, can shed light on the persistence of, and changes in, culturally-variable psychological processes.
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Reyes-García V, Balbo AL, Gomez-Baggethun E, Gueze M, Mesoudi A, Richerson P, Rubio-Campillo X, Ruiz-Mallén I, Shennan S (2016). Multilevel processes and cultural adaptation: Examples from past and present small-scale societies.
Ecol Soc,
21(4).
Abstract:
Multilevel processes and cultural adaptation: Examples from past and present small-scale societies.
Cultural adaptation has become central in the context of accelerated global change with authors increasingly acknowledging the importance of understanding multilevel processes that operate as adaptation takes place. We explore the importance of multilevel processes in explaining cultural adaptation by describing how processes leading to cultural (mis)adaptation are linked through a complex nested hierarchy, where the lower levels combine into new units with new organizations, functions, and emergent properties or collective behaviours. After a brief review of the concept of "cultural adaptation" from the perspective of cultural evolutionary theory and resilience theory, the core of the paper is constructed around the exploration of multilevel processes occurring at the temporal, spatial, social and political scales. We do so by examining small-scale societies' case studies. In each section, we discuss the importance of the selected scale for understanding cultural adaptation and then present an example that illustrates how multilevel processes in the selected scale help explain observed patterns in the cultural adaptive process. We end the paper discussing the potential of modelling and computer simulation for studying multilevel processes in cultural adaptation.
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Acerbi A, Tennie C, Mesoudi A (2016). Social learning solves the problem of narrow-peaked search landscapes: Experimental evidence in humans.
Royal Society Open Science,
3(9).
Abstract:
Social learning solves the problem of narrow-peaked search landscapes: Experimental evidence in humans
© 2016 the Authors. The extensive use of social learning is considered a major reason for the ecological success of humans. Theoretical considerations, models and experiments have explored the evolutionary basis of social learning, showing the conditions under which learning from others is more adaptive than individual learning. Here we present an extension of a previous experimental set-up, in which individuals go on simulated ‘hunts’ and their success depends on the features of a ‘virtual arrowhead’ they design. Individuals can modify their arrowhead either by individual trial and error or by copying others. We study how, in a multimodal adaptive landscape, the smoothness of the peaks influences learning. We compare narrow peaks, in which solutions close to optima do not provide useful feedback to individuals, to wide peaks, where smooth landscapes allow an effective hill-climbing individual learning strategy. We show that individual learning is more difficult in narrow-peaked landscapes, but that social learners perform almost equally well in both narrow- and wide-peaked search spaces. There was a weak trend for more copying in the narrow than wide condition, although as in previous experiments social information was generally underutilized. Our results highlight the importance of tasks’ design space when studying the adaptiveness of high-fidelity social learning.
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Mesoudi A, Chang L, Dall SRX, Thornton A (2016). The evolution of individual and cultural variation in social learning.
Trends in Ecology and Evolution,
31(3), 215-225.
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Henrich J, Boyd R, Derex M, Kline MA, Mesoudi A, Muthukrishna M, Powell AT, Shennan SJ, Thomas MG (2016). Understanding cumulative cultural evolution.
Proceedings of the National Academy of Sciences,
113(44), E6724-E6725.
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2015
Mesoudi A (2015). A Darwinian Theory of Cultural Evolution can Promote an Evolutionary Synthesis for the Social Sciences. Biological Theory, 2(3), 263-275.
Mesoudi A (2015). Biological and Cultural Evolution: Similar but Different. Biological Theory, 2(2), 119-123.
Mesoudi A (2015). Cultural Evolution: Overview. In (Ed)
International Encyclopedia of the Social & Behavioral Sciences: Second Edition, 388-393.
Abstract:
Cultural Evolution: Overview
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Priestley M, Mesoudi A (2015). Do Online Voting Patterns Reflect Evolved Features of Human Cognition? an Exploratory Empirical Investigation.
PLoS One,
10(6).
Abstract:
Do Online Voting Patterns Reflect Evolved Features of Human Cognition? an Exploratory Empirical Investigation.
Online votes or ratings can assist internet users in evaluating the credibility and appeal of the information which they encounter. For example, aggregator websites such as Reddit allow users to up-vote submitted content to make it more prominent, and down-vote content to make it less prominent. Here we argue that decisions over what to up- or down-vote may be guided by evolved features of human cognition. We predict that internet users should be more likely to up-vote content that others have also up-voted (social influence), content that has been submitted by particularly liked or respected users (model-based bias), content that constitutes evolutionarily salient or relevant information (content bias), and content that follows group norms and, in particular, prosocial norms. 489 respondents from the online social voting community Reddit rated the extent to which they felt different traits influenced their voting. Statistical analyses confirmed that norm-following and prosociality, as well as various content biases such as emotional content and originality, were rated as important motivators of voting. Social influence had a smaller effect than expected, while attitudes towards the submitter had little effect. This exploratory empirical investigation suggests that online voting communities can provide an important test-bed for evolutionary theories of human social information use, and that evolved features of human cognition may guide online behaviour just as it guides behaviour in the offline world.
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Mesoudi A, Chang L, Murray K, Lu HJ (2015). Higher frequency of social learning in China than in the West shows cultural variation in the dynamics of cultural evolution.
Proceedings of the Royal Society B,
282(1798), 20142209-20142209.
Abstract:
Higher frequency of social learning in China than in the West shows cultural variation in the dynamics of cultural evolution.
Cultural evolutionary models have identified a range of conditions under which social learning (copying others) is predicted to be adaptive relative to asocial learning (learning on one's own), particularly in humans where socially learned information can accumulate over successive generations. However, cultural evolution and behavioural economics experiments have consistently shown apparently maladaptive under-utilization of social information in Western populations. Here we provide experimental evidence of cultural variation in people's use of social learning, potentially explaining this mismatch. People in mainland China showed significantly more social learning than British people in an artefact-design task designed to assess the adaptiveness of social information use. People in Hong Kong, and Chinese immigrants in the UK, resembled British people in their social information use, suggesting a recent shift in these groups from social to asocial learning due to exposure to Western culture. Finally, Chinese mainland participants responded less than other participants to increased environmental change within the task. Our results suggest that learning strategies in humans are culturally variable and not genetically fixed, necessitating the study of the 'social learning of social learning strategies' whereby the dynamics of cultural evolution are responsive to social processes, such as migration, education and globalization.
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Acerbi A, Mesoudi A (2015). If we are all cultural Darwinians what’s the fuss about? Clarifying recent disagreements in the field of cultural evolution.
Biology and Philosophy,
30(4), 481-503.
Abstract:
If we are all cultural Darwinians what’s the fuss about? Clarifying recent disagreements in the field of cultural evolution
Cultural evolution studies are characterized by the notion that culture evolves accordingly to broadly Darwinian principles. Yet how far the analogy between cultural and genetic evolution should be pushed is open to debate. Here, we examine a recent disagreement that concerns the extent to which cultural transmission should be considered a preservative mechanism allowing selection among different variants, or a transformative process in which individuals recreate variants each time they are transmitted. The latter is associated with the notion of “cultural attraction”. This issue has generated much misunderstanding and confusion. We first clarify the respective positions, noting that there is in fact no substantive incompatibility between cultural attraction and standard cultural evolution approaches, beyond a difference in focus. Whether cultural transmission should be considered a preservative or reconstructive process is ultimately an empirical question, and we examine how both preservative and reconstructive cultural transmission has been studied in recent experimental research in cultural evolution. Finally, we discuss how the relative importance of preservative and reconstructive processes may depend on the granularity of analysis and the domain being studied.
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Aoki K, Mesoudi A (2015). Introduction to “learning strategies and cultural evolution during the palaeolithic”. In (Ed)
Learning Strategies and Cultural Evolution During the Palaeolithic, 1-8.
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Introduction to “learning strategies and cultural evolution during the palaeolithic”
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Mesoudi A, Aoki K (2015).
Learning Strategies and Cultural Evolution during the Palaeolithic., Springer.
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Learning Strategies and Cultural Evolution during the Palaeolithic
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Lycett SJ, Schillinger K, Kempe M, Mesoudi A (2015). Learning in the Acheulean: Experimental insights using handaxe form as a ‘model organism’. In (Ed)
Learning Strategies and Cultural Evolution During the Palaeolithic, 155-166.
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Learning in the Acheulean: Experimental insights using handaxe form as a ‘model organism’
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Mesoudi A, O’Brien MJ (2015). The Learning and Transmission of Hierarchical Cultural Recipes. Biological Theory, 3(1), 63-72.
Schillinger K, Mesoudi A, Lycett SJ (2015). The impact of imitative versus emulative learning mechanisms on artifactual variation: Implications for the evolution of material culture.
Evolution and Human BehaviorAbstract:
The impact of imitative versus emulative learning mechanisms on artifactual variation: Implications for the evolution of material culture
Cultural evolutionary approaches highlight that different social learning processes may be involved in the maintenance of cultural traditions. Inevitably, for traditions to be maintained, they must be transmitted with reasonably fidelity. It has been proposed that 'imitation' (i.e. the direct copying of actions of others displayed in tasks such as toolmaking) generates relatively low rates of copying error. As such, imitation has often been ascribed an important role in the maintenance of traditions and in the 'ratcheting' of technological complexity over time. Conversely, 'emulation' (i.e. the copying of a result but not the behaviors that have led to that result) is allegedly associated with the production of relatively higher rates of copying error. However, to what extent these different social learning mechanisms generate distinct patterns of variation during the manufacture of material traditions remains largely unexplored empirically. Here, a controlled experiment was implemented using 60 participants who copied the shape of a 3D 'target handaxe form' from a standardized foam block. In an 'imitation condition', 30 participants were shown manufacturing techniques employed in the production of the target form and the target form itself. Conversely, in an 'emulation condition', 30 participants were shown only the (target) form. Copying error rates were statistically different, being significantly lower in the 'imitation' condition compared to the 'emulation' condition. Moreover, participants in the imitation condition matched the demonstrated behaviors with significantly higher copying fidelity than the alternative condition. These results illustrate that imitation may be imperative for the long-term perpetuation of visibly distinct archaeological traditions, especially in the case of lithic (reductive) traditions, where copying error rates can be expected to be relatively high. These findings, therefore, provide evidence that imitation may be required to explain the prolonged continuity of broad shape fidelity such as that seen in traditions of 'handaxe' manufacture during the Pleistocene.
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O’Brien MJ, Buchanan B, Boulanger MT, Mesoudi A, Collard M, Eren MI, Alexander Bentley R, Lee Lyman R (2015). Transmission of cultural variants in the North American paleolithic. In (Ed)
Learning Strategies and Cultural Evolution During the Palaeolithic, 121-143.
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Transmission of cultural variants in the North American paleolithic
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2014
Kempe M, Mesoudi A (2014). An experimental demonstration of the effect of group size on cultural accumulation.
Evolution and Human Behavior,
35(4), 285-290.
Abstract:
An experimental demonstration of the effect of group size on cultural accumulation
Cumulative culture is thought to have played a major role in hominin evolution, and so an understanding of the factors that affect cultural accumulation is important for understanding human evolution. Population size may be one such factor, with larger populations thought to be able to support more complex cultural traits. This hypothesis has been suggested by mathematical models and empirical studies of small-scale societies. However, to date there have been few experimental demonstrations of an effect of population size on cultural accumulation. Here we provide such a demonstration using a novel task, solving jigsaw puzzles. 80 participants divided into ten transmission chains solved puzzles in one of two conditions: one in which participants had access to one semi-completed puzzle from the previous generation, and the other in which participants simultaneously saw three semi-completed puzzles from the previous generation. As predicted, the mean number of pieces solved increased over time in the three-puzzle-per-generation condition, but not in the one-puzzle-per-generation condition. Thus, our experiment provides support for a hypothesized relationship between population size and cultural accumulation. In particular, our results suggest that the ability to simultaneously learn from multiple cultural models, and combine the knowledge of those multiple models, is most likely to allow larger groups to support more complex culture. © 2014 Elsevier Inc.
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Schillinger K, Mesoudi A, Lycett SJ (2014). Considering the role of time budgets on copy-error rates in material culture traditions: an experimental assessment.
PLoS One,
9(5).
Abstract:
Considering the role of time budgets on copy-error rates in material culture traditions: an experimental assessment.
Ethnographic research highlights that there are constraints placed on the time available to produce cultural artefacts in differing circumstances. Given that copying error, or cultural 'mutation', can have important implications for the evolutionary processes involved in material culture change, it is essential to explore empirically how such 'time constraints' affect patterns of artefactual variation. Here, we report an experiment that systematically tests whether, and how, varying time constraints affect shape copying error rates. A total of 90 participants copied the shape of a 3D 'target handaxe form' using a standardized foam block and a plastic knife. Three distinct 'time conditions' were examined, whereupon participants had either 20, 15, or 10 minutes to complete the task. One aim of this study was to determine whether reducing production time produced a proportional increase in copy error rates across all conditions, or whether the concept of a task specific 'threshold' might be a more appropriate manner to model the effect of time budgets on copy-error rates. We found that mean levels of shape copying error increased when production time was reduced. However, there were no statistically significant differences between the 20 minute and 15 minute conditions. Significant differences were only obtained between conditions when production time was reduced to 10 minutes. Hence, our results more strongly support the hypothesis that the effects of time constraints on copying error are best modelled according to a 'threshold' effect, below which mutation rates increase more markedly. Our results also suggest that 'time budgets' available in the past will have generated varying patterns of shape variation, potentially affecting spatial and temporal trends seen in the archaeological record. Hence, 'time-budgeting' factors need to be given greater consideration in evolutionary models of material culture change.
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Schillinger K, Mesoudi A, Lycett SJ (2014). Copying error and the cultural evolution of "Additive" vs. "Reductive" material traditions: an experimental assessment.
American Antiquity,
79(1), 128-143.
Abstract:
Copying error and the cultural evolution of "Additive" vs. "Reductive" material traditions: an experimental assessment
Copyright © 2014 by the Society for American Archaeology. Copying errors that occur during the manufacture of artifactual traditions are potentially a major source of variation. It has been proposed that material items produced via "additive" processes (e.g. pottery) will possess less variation than traditions produced via "reductive" processes (e.g. stone knapping). The logic of this premise is that "additive" production methods more readily allow for the reversal of copying errors compared to strictly "reductive-only" processes. Here, we tested this hypothesis in shape data using an experimental framework in which we generated and statistically analyzed mor-phometric (size-adjusted) shape data under controlled and replicable conditions. Participants engaged in one of two alternative conditions: an irreversible ("reductive-only") manufacturing process or a reversible ("additive-reductive") process. With a number of factors held constant, participants were required to copy the shape of a "target form" as accurately as possible using a standardized block of plasticine and a steel table knife. Results demonstrated statistically greater levels of shape-copying errors in the replicas produced in the reductive-only condition. This indicates that "mutation rates" in the shape attributes of artifactual traditions produced via reductive processes are inherently greater than those produced via alternative means. Several implications for the study of variation in artifactual traditions are discussed.
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Mesoudi A (2014). Cultural evolution in more than two dimensions: distinguishing social learning biases and identifying payoff structures.
Behav Brain Sci,
37(1), 91-92.
Abstract:
Cultural evolution in more than two dimensions: distinguishing social learning biases and identifying payoff structures.
Bentley et al.'s two-dimensional conceptual map is complementary to cultural evolution research that has sought to explain population-level cultural dynamics in terms of individual-level behavioral processes. Here, I qualify their scheme by arguing that different social learning biases should be treated distinctly, and that the transparency of decisions is sometimes conflated with the actual underlying payoff structure of those decisions.
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Kempe M, Mesoudi A (2014). Experimental and theoretical models of human cultural evolution.
WIREs Cognitive Science,
5, 317-326.
Abstract:
Experimental and theoretical models of human cultural evolution
The modern field of cultural evolution is now over 30 years old, and an extensive body of theory and data has been amassed. This article reviews models of cultural evolution, both experimental and theoretical, and surveys what they can tell us about cultural evolutionary processes. The models are grouped according to which of four broad questions they address: (1) How are cultural traits changed during transmission? (2) How and why do cultural traits accumulate over time? (3) What social learning biases do people use? and (4) What are the population-level consequences of different social learning biases? We conclude by highlighting gaps in the literature and promising future research directions, including the further integration of theoretical models and experimental data, the identification of the factors underlying cumulative cultural evolution, and the explanation of individual and cultural variation in social learning biases.
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Kempe M, Lycett SJ, Mesoudi A (2014). From cultural traditions to cumulative culture: parameterizing the differences between human and nonhuman culture.
Journal of Theoretical Biology,
359, 29-36.
Abstract:
From cultural traditions to cumulative culture: parameterizing the differences between human and nonhuman culture.
Diverse species exhibit cultural traditions, i.e. population-specific profiles of socially learned traits, from songbird dialects to primate tool-use behaviours. However, only humans appear to possess cumulative culture, in which cultural traits increase in complexity over successive generations. Theoretically, it is currently unclear what factors give rise to these phenomena, and consequently why cultural traditions are found in several species but cumulative culture in only one. Here, we address this by constructing and analysing cultural evolutionary models of both phenomena that replicate empirically attestable levels of cultural variation and complexity in chimpanzees and humans. In our model of cultural traditions (Model 1), we find that realistic cultural variation between populations can be maintained even when individuals in different populations invent the same traits and migration between populations is frequent, and under a range of levels of social learning accuracy. This lends support to claims that putative cultural traditions are indeed cultural (rather than genetic) in origin, and suggests that cultural traditions should be widespread in species capable of social learning. Our model of cumulative culture (Model 2) indicates that both the accuracy of social learning and the number of cultural demonstrators interact to determine the complexity of a trait that can be maintained in a population. Combining these models (Model 3) creates two qualitatively distinct regimes in which there are either a few, simple traits, or many, complex traits. We suggest that these regimes correspond to nonhuman and human cultures, respectively. The rarity of cumulative culture in nature may result from this interaction between social learning accuracy and number of demonstrators.
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2013
Mesoudi A, Blanchet S, Charmantier A, Danchin E, Fogarty L, Jablonka E, Laland KN, Morgan TJH, Muller GB, Odling-Smee FJ, et al (2013). Is non-genetic inheritance just a proximate mechanism? a corroboration of the Extended Evolutionary Synthesis. Biological Theory, 7
Pitcher BJ, Mesoudi A, McElligott AG (2013). Sex-biased sound symbolism in english-language first names.
PLoS One,
8(6).
Abstract:
Sex-biased sound symbolism in english-language first names.
Sexual selection has resulted in sex-based size dimorphism in many mammals, including humans. In Western societies, average to taller stature men and comparatively shorter, slimmer women have higher reproductive success and are typically considered more attractive. This size dimorphism also extends to vocalisations in many species, again including humans, with larger individuals exhibiting lower formant frequencies than smaller individuals. Further, across many languages there are associations between phonemes and the expression of size (e.g. large /a, o/, small /i, e/), consistent with the frequency-size relationship in vocalisations. We suggest that naming preferences are a product of this frequency-size relationship, driving male names to sound larger and female names smaller, through sound symbolism. In a 10-year dataset of the most popular British, Australian and American names we show that male names are significantly more likely to contain larger sounding phonemes (e.g. "Thomas"), while female names are significantly more likely to contain smaller phonemes (e.g. "Emily"). The desire of parents to have comparatively larger, more masculine sons, and smaller, more feminine daughters, and the increased social success that accompanies more sex-stereotyped names, is likely to be driving English-language first names to exploit sound symbolism of size in line with sexual body size dimorphism.
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Mesoudi A (2013). Studying cultural transmission with in an interdisciplinary cultural evolutionary framework. In (Ed) Understanding Cultural Transmission in Anthropology: a Critical Synthesis, 131-147.
2012
Atkisson C, O'Brien MJ, Mesoudi A (2012). Adult learners in a novel environment use prestige-biased social learning.
Evol Psychol,
10(3), 519-537.
Abstract:
Adult learners in a novel environment use prestige-biased social learning.
Social learning (learning from others) is evolutionarily adaptive under a wide range of conditions and is a long-standing area of interest across the social and biological sciences. One social-learning mechanism derived from cultural evolutionary theory is prestige bias, which allows a learner in a novel environment to quickly and inexpensively gather information as to the potentially best teachers, thus maximizing his or her chances of acquiring adaptive behavior. Learners provide deference to high-status individuals in order to ingratiate themselves with, and gain extended exposure to, that individual. We examined prestige-biased social transmission in a laboratory experiment in which participants designed arrowheads and attempted to maximize hunting success, measured in caloric return. Our main findings are that (1) participants preferentially learned from prestigious models (defined as those models at whom others spent longer times looking), and (2) prestige information and success-related information were used to the same degree, even though the former was less useful in this experiment than the latter. We also found that (3) participants were most likely to use social learning over individual (asocial) learning when they were performing poorly, in line with previous experiments, and (4) prestige information was not used more often following environmental shifts, contrary to predictions. These results support previous discussions of the key role that prestige-biased transmission plays in social learning.
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Kempe M, Lycett S, Mesoudi A (2012). An experimental test of the accumulated copying error model of cultural mutation for Acheulean handaxe size.
PLoS One,
7(11).
Abstract:
An experimental test of the accumulated copying error model of cultural mutation for Acheulean handaxe size.
Archaeologists interested in explaining changes in artifact morphology over long time periods have found it useful to create models in which the only source of change is random and unintentional copying error, or 'cultural mutation'. These models can be used as null hypotheses against which to detect non-random processes such as cultural selection or biased transmission. One proposed cultural mutation model is the accumulated copying error model, where individuals attempt to copy the size of another individual's artifact exactly but make small random errors due to physiological limits on the accuracy of their perception. Here, we first derive the model within an explicit mathematical framework, generating the predictions that multiple independently-evolving artifact chains should diverge over time such that their between-chain variance increases while the mean artifact size remains constant. We then present the first experimental test of this model in which 200 participants, split into 20 transmission chains, were asked to faithfully copy the size of the previous participant's handaxe image on an iPad. The experimental findings supported the model's prediction that between-chain variance should increase over time and did so in a manner quantitatively in line with the model. However, when the initial size of the image that the participants resized was larger than the size of the image they were copying, subjects tended to increase the size of the image, resulting in the mean size increasing rather than staying constant. This suggests that items of material culture formed by reductive vs. additive processes may mutate differently when individuals attempt to replicate faithfully the size of previously-produced artifacts. Finally, we show that a dataset of 2601 Acheulean handaxes shows less variation than predicted given our empirically measured copying error variance, suggesting that other processes counteracted the variation in handaxe size generated by perceptual cultural mutation.
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Mesoudi A, Jensen K (2012). Culture and the Evolution of Human Sociality. In (Ed)
The Oxford Handbook of Comparative Evolutionary Psychology.
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Culture and the Evolution of Human Sociality
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Mesoudi A, O'Brien MJ (2012). Statistical analyses cannot be divorced from archaeological theory: a reply to potter.
American Antiquity,
77(2), 372-375.
Abstract:
Statistical analyses cannot be divorced from archaeological theory: a reply to potter
Potter criticizes our experimental study of the roles played by indirect bias and guided variation in shaping prehistoric Great Basin projectile point variation. His criticisms are technically correct from the standpoint of statistical convention, but he fails to understand the theoretical rationale of our study. Without such an understanding, hi s assertion that our conclusions are questionable is incorrect. Here we point out again (1) how our experimental work bridges the gap between cultural-transmission theory and the empirical record and (2) why our conclusions are indeed valid. Copyright © 2012 by the Society for American Archaeology.
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2011
Mesoudi A (2011). An experimental comparison of human social learning strategies: Payoff-biased social learning is adaptive but underused.
Evolution and Human Behavior,
32(5), 334-342.
Abstract:
An experimental comparison of human social learning strategies: Payoff-biased social learning is adaptive but underused
Analytical models have identified a set of social learning strategies that are predicted to be adaptive relative to individual (asocial) learning. In the present study, human participants engaged in an ecologically valid artifact-design task with the opportunity to engage in a range of social learning strategies: payoff bias, conformity, averaging and random copying. The artifact (an arrowhead) was composed of multiple continuous and discrete attributes which jointly generated a complex multimodal adaptive landscape that likely reflects actual cultural fitness environments. Participants exhibited a mix of individual learning and payoff-biased social learning, with negligible frequencies of the other social learning strategies. This preference for payoff-biased social learning was evident from the initial trials, suggesting that participants came into the study with an intrinsic preference for this strategy. There was also a small but significant increase in the frequency of payoff-biased social learning over sessions, suggesting that strategy choice may itself be subject to learning. Frequency of payoff-biased social learning predicted both absolute and relative success in the task, especially in a multimodal (rather than unimodal) fitness environment. This effect was driven by a minority of hardcore social learners who copied the best group member on more than half of trials. These hardcore social learners were also above-average individual learners, suggesting a link between individual and social learning ability. The lower-than-expected frequency of social learning may reflect the existence of information producer-scrounger dynamics in human populations. © 2011 Elsevier Inc.
Abstract.
Danchin É, Charmantier A, Champagne FA, Mesoudi A, Pujol B, Blanchet S (2011). Beyond DNA: integrating inclusive inheritance into an extended theory of evolution.
Nature Reviews Genetics,
12(7), 475-486.
Abstract:
Beyond DNA: integrating inclusive inheritance into an extended theory of evolution.
Many biologists are calling for an 'extended evolutionary synthesis' that would 'modernize the modern synthesis' of evolution. Biological information is typically considered as being transmitted across generations by the DNA sequence alone, but accumulating evidence indicates that both genetic and non-genetic inheritance, and the interactions between them, have important effects on evolutionary outcomes. We review the evidence for such effects of epigenetic, ecological and cultural inheritance and parental effects, and outline methods that quantify the relative contributions of genetic and non-genetic heritability to the transmission of phenotypic variation across generations. These issues have implications for diverse areas, from the question of missing heritability in human complex-trait genetics to the basis of major evolutionary transitions.
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Mesoudi A (2011).
Cultural Evolution How Darwinian Theory can Explain Human Culture and Synthesize the Social Sciences., University of Chicago Press.
Abstract:
Cultural Evolution How Darwinian Theory can Explain Human Culture and Synthesize the Social Sciences
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Mesoudi A (2011). Culture and the Darwinian renaissance in the social sciences and humanities.
Journal of Evolutionary Psychology,
9(2), 109-124.
Abstract:
Culture and the Darwinian renaissance in the social sciences and humanities
A "Darwinian Renaissance" in the social sciences and humanities cannot occur until evolutionary theory can successfully explain rapid and cumulative cultural change. Here I review empirical evidence that much of human behaviour is culturally determined, emphasising the need to incorporate culture into evolutionary analyses of human behaviour. I also review theoretical work which shows that culture is genetically adaptive, belying any simplistic gene-culture dichotomy. Finally, I show how recent work analysing culture as an evolutionary system is beginning to answer the kinds of questions that are of interest to social scientists and humanities scholars. These include phylogenetic reconstructions of the historical relationships between languages, manuscripts, social customs and artifacts, and experimental simulations of the microevolutionary processes underlying patterns of cultural macroevolution.
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Mesoudi A (2011). Darwinian Sociocultural Evolution: Solutions to Dilemmas in Cultural and Social Theory.
JOURNAL OF ANTHROPOLOGICAL RESEARCH,
67(1), 157-158.
Author URL.
Mesoudi A (2011). Evolutionary psychology meets cultural psychology. Journal of Evolutionary Psychology, 9(1), 83-87.
Chittka L, Mesoudi A (2011). Insect Swarm Intelligence. Science, 331(6016), 401-402.
Mesoudi A, McElligott AG, Adger D (2011). Introduction: integrating genetic and cultural evolutionary approaches to language.
Hum Biol,
83(2), 141-151.
Abstract:
Introduction: integrating genetic and cultural evolutionary approaches to language.
The papers in this special issue of Human Biology address recent research in the field of language evolution, both the genetic evolution of the language faculty and the cultural evolution of specific languages. While both of these areas have received increasing interest in recent years, there is also a need to integrate these somewhat separate efforts and explore the relevant gene-culture coevolutionary interactions. Here we summarize the individual contributions, set them in the context of the wider literature, and identify outstanding future research questions. The first set of papers concerns the comparative study of nonhuman communication in primates and birds from both a behavioral and neurobiological perspective, revealing evidence for several common language-related traits in various nonhuman species and providing clues as to the evolutionary origin and function of the human language faculty. The second set of papers discusses the consequences of viewing language as a culturally evolving system in its own right, including claims that this removes the need for strong genetic biases for language acquisition, and that phylogenetic evolutionary methods can be used to reconstruct language histories. We conclude by highlighting outstanding areas for future research, including identifying the precise selection pressures that gave rise to the language faculty in ancestral hominin species, and determining the strength, domain specificity, and origin of the cultural transmission biases that shape languages as they pass along successive generations of language learners.
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Mesoudi A (2011). Variable cultural acquisition costs constrain cumulative cultural evolution.
PLoS One,
6(3).
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Variable cultural acquisition costs constrain cumulative cultural evolution.
One of the hallmarks of the human species is our capacity for cumulative culture, in which beneficial knowledge and technology is accumulated over successive generations. Yet previous analyses of cumulative cultural change have failed to consider the possibility that as cultural complexity accumulates, it becomes increasingly costly for each new generation to acquire from the previous generation. In principle this may result in an upper limit on the cultural complexity that can be accumulated, at which point accumulated knowledge is so costly and time-consuming to acquire that further innovation is not possible. In this paper I first review existing empirical analyses of the history of science and technology that support the possibility that cultural acquisition costs may constrain cumulative cultural evolution. I then present macroscopic and individual-based models of cumulative cultural evolution that explore the consequences of this assumption of variable cultural acquisition costs, showing that making acquisition costs vary with cultural complexity causes the latter to reach an upper limit above which no further innovation can occur. These models further explore the consequences of different cultural transmission rules (directly biased, indirectly biased and unbiased transmission), population size, and cultural innovations that themselves reduce innovation or acquisition costs.
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2010
O'Brien MJ, Lyman RL, Mesoudi A, VanPool TL (2010). Cultural traits as units of analysis.
Philos Trans R Soc Lond B Biol Sci,
365(1559), 3797-3806.
Abstract:
Cultural traits as units of analysis.
Cultural traits have long been used in anthropology as units of transmission that ostensibly reflect behavioural characteristics of the individuals or groups exhibiting the traits. After they are transmitted, cultural traits serve as units of replication in that they can be modified as part of an individual's cultural repertoire through processes such as recombination, loss or partial alteration within an individual's mind. Cultural traits are analogous to genes in that organisms replicate them, but they are also replicators in their own right. No one has ever seen a unit of transmission, either behavioural or genetic, although we can observe the effects of transmission. Fortunately, such units are manifest in artefacts, features and other components of the archaeological record, and they serve as proxies for studying the transmission (and modification) of cultural traits, provided there is analytical clarity over how to define and measure the units that underlie this inheritance process.
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Mesoudi A, Veldhuis D, Foley RA (2010). Why aren't the social sciences Darwinian?. Journal of Evolutionary Psychology, 8, 93-104.
2009
Mesoudi A (2009). How cultural evolutionary theory can inform social psychology and vice versa.
Psychol Rev,
116(4), 929-952.
Abstract:
How cultural evolutionary theory can inform social psychology and vice versa.
Cultural evolutionary theory is an interdisciplinary field in which human culture is viewed as a Darwinian process of variation, competition, and inheritance, and the tools, methods, and theories developed by evolutionary biologists to study genetic evolution are adapted to study cultural change. It is argued here that an integration of the theories and findings of mainstream social psychology and of cultural evolutionary theory can be mutually beneficial. Social psychology provides cultural evolution with a set of empirically verified microevolutionary cultural processes, such as conformity, model-based biases, and content biases, that are responsible for specific patterns of cultural change. Cultural evolutionary theory provides social psychology with ultimate explanations for, and an understanding of the population-level consequences of, many social psychological phenomena, such as social learning, conformity, social comparison, and intergroup processes, as well as linking social psychology with other social science disciplines such as cultural anthropology, archaeology, and sociology.
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Mesoudi A, O'Brien MJ (2009). Placing archaeology within a unified science of cultural evolution. In (Ed) Pattern and Process in Cultural Evolution, 21-32.
Mesoudi A, Lycett SJ (2009). Random copying, frequency-dependent copying and culture change.
Evolution and Human Behavior,
30(1), 41-48.
Abstract:
Random copying, frequency-dependent copying and culture change
Previous evolutionary analyses of human culture have found that a simple model of random copying, analogous to neutral genetic drift, can generate the distinct power-law frequency distribution of cultural traits that is typical of various real-world cultural datasets, such as first names, patent citations and prehistoric pottery types. Here, we use agent-based simulations to explore the effects of frequency-dependent copying (e.g. conformity and anti-conformity) on this power-law distribution. We find that when traits are actively selected on the basis of their frequency, then the power-law distribution is severely disrupted. Conformity generates a "winner-takes-all" distribution in which popular traits dominate, while anti-conformity generates a "humped" distribution in which traits of intermediate frequency are favoured. However, a more passive frequency-dependent "trimming", in which traits are selectively ignored on the basis of their frequency, generates reasonable approximations to the power-law distribution. This frequency-dependent trimming may therefore be difficult to distinguish from genuine random copying using population-level data alone. Implications for the study of both human and nonhuman culture are discussed. © 2009 Elsevier Inc. All rights reserved.
Abstract.
Mesoudi A (2009). The cultural dynamics of copycat suicide.
PLoS One,
4(9).
Abstract:
The cultural dynamics of copycat suicide.
The observation that suicides sometimes cluster in space and/or time has led to suggestions that these clusters are caused by the social learning of suicide-related behaviours, or "copycat suicides". Point clusters are clusters of suicides localised in both time and space, and have been attributed to direct social learning from nearby individuals. Mass clusters are clusters of suicides localised in time but not space, and have been attributed to the dissemination of information concerning celebrity suicides via the mass media. Here, agent-based simulations, in combination with scan statistic methods for detecting clusters of rare events, were used to clarify the social learning processes underlying point and mass clusters. It was found that social learning between neighbouring agents did generate point clusters as predicted, although this effect was partially mimicked by homophily (individuals preferentially assorting with similar others). The one-to-many transmission dynamics characterised by the mass media were shown to generate mass clusters, but only where social learning was weak, perhaps due to prestige bias (only copying prestigious celebrities) and similarity bias (only copying similar models) acting to reduce the subset of available models. These findings can help to clarify and formalise existing hypotheses and to guide future empirical work relating to real-life copycat suicides.
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2008
Mesoudi A (2008). An experimental simulation of the "copy-successful-individuals" cultural learning strategy: adaptive landscapes, producer-scrounger dynamics, and informational access costs.
Evolution and Human Behavior,
29(5), 350-363.
Abstract:
An experimental simulation of the "copy-successful-individuals" cultural learning strategy: adaptive landscapes, producer-scrounger dynamics, and informational access costs
An experimental simulation of cultural evolution was conducted using the virtual arrowhead task. Participants designed "virtual arrowheads" and tested them in "virtual hunting environments", improving their designs through either individual trial-and-error learning or by copying the design of another participant. A previous study using this task [Mesoudi, A. & O'Brien, M. J. (2008). The cultural transmission of Great Basin projectile point technology I: an experimental simulation. American Antiquity, 73, 3-28.] found that a cultural learning strategy of "copy-successful-individuals" was significantly more adaptive than individual learning. The present study explored the robustness of this finding using the same task but under different conditions. It was found that (a) individual learning was significantly more adaptive in a unimodal adaptive landscape than in a multimodal adaptive landscape, suggesting that the adaptive advantage of cultural learning would disappear in unimodal environments; (b) the adaptive advantage of copy-successful-individuals was maintained when cultural learning was permitted at regular intervals, despite the increased opportunity for information scroungers to inhibit exploration of the environment, because participants flexibly switched between individual and cultural learning depending on circumstances; (c) allowing participants to set access costs that other participants must pay in order to view their designs severely curtailed the use of cultural learning and especially the copy-successful-individuals strategy. © 2008 Elsevier Inc. All rights reserved.
Abstract.
Mesoudi A, Danielson P (2008). Ethics, evolution and culture.
Theory Biosci,
127(3), 229-240.
Abstract:
Ethics, evolution and culture.
Recent work in the fields of evolutionary ethics and moral psychology appears to be converging on a single empirically- and evolutionary-based science of morality or ethics. To date, however, these fields have failed to provide an adequate conceptualisation of how culture affects the content and distribution of moral norms. This is particularly important for a large class of moral norms relating to rapidly changing technological or social environments, such as norms regarding the acceptability of genetically modified organisms. Here we suggest that a science of morality/ethics can benefit from adopting a cultural evolution or gene-culture coevolution approach, which treats culture as a second, separate evolutionary system that acts in parallel to biological/genetic evolution. This cultural evolution approach brings with it a set of established theoretical concepts (e.g. different cultural transmission mechanisms) and empirical methods (e.g. evolutionary game theory) that can significantly improve our understanding of human morality.
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Mesoudi A (2008). Foresight in cultural evolution.
Biology and Philosophy,
23(2), 243-255.
Abstract:
Foresight in cultural evolution
Critics of Darwinian cultural evolution frequently assert that whereas biological evolution is blind and undirected, cultural change is directed or guided by people who possess foresight, thereby invalidating any Darwinian analysis of culture. Here I show this argument to be erroneous and unsupported in several respects. First, critics commonly conflate human foresight with supernatural clairvoyance, resulting in the premature rejection of Darwinian cultural evolution on false logical grounds. Second, the presence of foresight is perfectly consistent with Darwinian evolution, and is found in biology, in the form of open, teleonomic processes such as genetically-biased behavioural learning. Finally, empirical evidence from the social sciences suggests that cultural change appears far less guided and directed, and human foresight far less accurate, than is commonly assumed. © Springer Science+Business Media B.V. 2007.
Abstract.
Danielson P, Mesoudi A, Stanev R (2008). NERD and norms: Framework and experiments.
Philosophy of Science,
75(5), 830-842.
Abstract:
NERD and norms: Framework and experiments
We advocate and share the same theoretical framework for empirical research in ethics as exemplified in Christina Bicchieri's the Grammar of Society. Our research differs from Bicchieri's in our approach to experimentation: where she relies on lab experiments, we have constructed an experimental platform based on an internet survey instrument; where she relies on rational reconstructions, we do not. In this paper we focus on four contrasts in our methods: (1) we provide a space to explore ethical influence and norm transmission between participants, belief and choice revision, and reputation over time; (2) we provide ways for participants to expand the context of their and others' decisions; (3) we focus on more realistic ethical decisions than is allowed by games; and (4) we explain why Bicchieri's method of rational reconstructions presents challenges to her theory of social norms. Our methods are complementary to Bicchieri's, and together we can work toward developing more comprehensive empirically informed ethics. Copyright 2008 by the Philosophy of Science Association. All rights reserved.
Abstract.
Whiten A, Mesoudi A (2008). Review. Establishing an experimental science of culture: animal social diffusion experiments.
Philos Trans R Soc Lond B Biol Sci,
363(1509), 3477-3488.
Abstract:
Review. Establishing an experimental science of culture: animal social diffusion experiments.
A growing set of observational studies documenting putative cultural variations in wild animal populations has been complemented by experimental studies that can more rigorously distinguish between social and individual learning. However, these experiments typically examine only what one animal learns from another. Since the spread of culture is inherently a group-level phenomenon, greater validity can be achieved through 'diffusion experiments', in which founder behaviours are experimentally manipulated and their spread across multiple individuals tested. Here we review the existing corpus of 33 such studies in fishes, birds, rodents and primates and offer the first systematic analysis of the diversity of experimental designs that have arisen. We distinguish three main transmission designs and seven different experimental/control approaches, generating an array with 21 possible cells, 15 of which are currently represented by published studies. Most but not all of the adequately controlled diffusion experiments have provided robust evidence for cultural transmission in at least some taxa, with transmission spreading across populations of up to 24 individuals and along chains of up to 14 transmission events. We survey the achievements of this work, its prospects for the future and its relationship to diffusion studies with humans discussed in this theme issue and elsewhere.
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Mesoudi A, Whiten A (2008). Review. The multiple roles of cultural transmission experiments in understanding human cultural evolution.
Philos Trans R Soc Lond B Biol Sci,
363(1509), 3489-3501.
Abstract:
Review. The multiple roles of cultural transmission experiments in understanding human cultural evolution.
In this paper, we explore how experimental studies of cultural transmission in adult humans can address general questions regarding the 'who, what, when and how' of human cultural transmission, and consequently inform a theory of human cultural evolution. Three methods are discussed. The transmission chain method, in which information is passed along linear chains of participants, has been used to identify content biases in cultural transmission. These concern the kind of information that is transmitted. Several such candidate content biases have now emerged from the experimental literature. The replacement method, in which participants in groups are gradually replaced or moved across groups, has been used to study phenomena such as cumulative cultural evolution, cultural group selection and cultural innovation. The closed-group method, in which participants learn in groups with no replacement, has been used to explore issues such as who people choose to learn from and when they learn culturally as opposed to individually. A number of the studies reviewed here have received relatively little attention within their own disciplines, but we suggest that these, and future experimental studies of cultural transmission that build on them, can play an important role in a broader science of cultural evolution.
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Author URL.
Mesoudi A, O'Brien MJ (2008). The cultural transmission of great basin projectile-point technology I: an experimental simulation.
American Antiquity,
73(1), 3-28.
Abstract:
The cultural transmission of great basin projectile-point technology I: an experimental simulation
A Darwinian evolutionary approach to archaeology naturally leads to a focus on cultural transmission. Theoretical models of cultural evolution indicate that individual-level details of cultural transmission can have specific and significant population-level effects, implying that differences in transmission may be detectable in the archaeological record. Here we present an experimental simulation of the cultural transmission of prehistoric projectile-point technology, simulating the two transmission modes-indirect bias and guided variation-that Bettinger and Eerkens (1999) suggested were responsible for differences in Nevada and California point-attribute correlations. Groups of participants designed "virtual projectile points" and tested them in "virtual hunting environments," with different phases of learning simulating, alternately, indirectly biased cultural transmission and independent individual learning. As predicted, periods of cultural transmission were associated with significantly stronger attribute correlations than were periods of individual learning. We also found that participants who could engage in indirectly biased horizontal cultural transmission outperformed individual-learning controls, especially when individual learning was costly and the selective environment was multimodal. The study demon-strates that experimental simulations of cultural transmission, used alongside archaeological data, mathematical models and computer simulations, constitute a useful tool for studying cultural change. Copyright ©2008 by the Society for American Archaeology.
Abstract.
Mesoudi A, O'Brien MJ (2008). The cultural transmission of great basin projectile-point technology II: an agent-based computer simulation.
American Antiquity,
73(4), 627-644.
Abstract:
The cultural transmission of great basin projectile-point technology II: an agent-based computer simulation
We present an agent-based computer simulation that extends a previous experimental simulation (Mesoudi and O'Brien 2008) of the cultural transmission of projectile-point technology in the prehistoric Great Basin, with participants replaced with computer-generated agents. As in the experiment, individual learning is found to generate low correlations between artifact attributes, whereas indirectly biased cultural transmission (copying the point design of the most successful hunter) generates high correlations between artifact attributes. These results support the hypothesis that low attribute correlations in prehistoric California resulted from individual learning, and high attribute correlations in prehistoric Nevada resulted from indirectly biased cultural transmission. However, alternative modes of cultural transmission, including conformist transmission and random copying, generated similarly high attribute correlations as indirect bias, suggesting that it may be difficult to infer which transmission rule generated this archaeological pattern. On the other hand, indirect bias outperformed all other cultural-transmission rules, lending plausibility to the original hypothesis. Importantly, this advantage depends on the assumption of a multimodal adaptive landscape in which there are multiple locally optimal artifact designs. Indeed, in unimodal fitness environments no cultural transmission rule outperformed individual learning, highlighting how the shape of the adaptive landscape within which cultural evolution occurs can strongly influence the dynamics of cultural transmission. Generally, experimental and computer simulations can be useful in answering questions that are difficult to address with archaeological data, such as identifying the consequences of different modes of cultural transmission or exploring the effect of different selective environments. Copyright © 2008 by the Society for American Archaeology.
Abstract.
2007
Mesoudi A, Laland KN (2007). Culturally transmitted paternity beliefs and the evolution of human mating behaviour.
Proc Biol Sci,
274(1615), 1273-1278.
Abstract:
Culturally transmitted paternity beliefs and the evolution of human mating behaviour.
Recent anthropological findings document how certain lowland South American societies hold beliefs in 'partible paternity', which allow children to have more than one 'biological' father. This contrasts with Western beliefs in 'singular paternity', and biological reality, where children have just one father. Here, mathematical models are used to explore the coevolution of paternity beliefs and the genetic variation underlying human mating behaviour. A gene-culture coevolutionary model found that populations exposed to a range of selection regimes typically converge on one of two simultaneously stable equilibria; one where the population is monogamous and believes in singular paternity, and the other where the population is polygamous and believes in partible paternity. A second agent-based model, with alternative assumptions regarding the formation of mating consortships, broadly replicated this finding in populations with a strongly female-biased sex ratio, consistent with evidence for high adult male mortality in the region. This supports an evolutionary scenario in which ancestral South American populations with differing paternity beliefs were subject to divergent selection on genetically influenced mating behaviour, facilitated by a female-biased sex ratio, leading to the present-day associations of female control, partible paternity and polygamy in some societies, and male control, singular paternity and monogamy in others.
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Author URL.
Mesoudi A (2007). Extended evolutionary theory makes human culture more amenable to evolutionary analysis.
Behavioral and Brain Sciences,
30(4).
Abstract:
Extended evolutionary theory makes human culture more amenable to evolutionary analysis
Jablonka & Lamb's (J&L's) extended evolutionary theory is more amenable to being applied to human cultural change than standard neo-Darwinian evolutionary theory. However, the authors are too quick to dismiss past evolutionary approaches to human culture. They also overlook a potential parallel between evolved genetic mechanisms that enhance evolvability and learned cognitive mechanisms that enhance learnability. © 2007 Cambridge University Press.
Abstract.
Mesoudi A, Laland KN (2007). Extending the behavioral sciences framework: Clarification of methods, predictions, and concepts.
Behavioral and Brain Sciences,
30(1), 36-37.
Abstract:
Extending the behavioral sciences framework: Clarification of methods, predictions, and concepts
We applaud Gintis's attempt to provide an evolutionary-based framework for the behavioral sciences, and note a number of similarities with our own recent cultural evolutionary structure for the social sciences. Gintis's proposal would be further strengthened by a greater emphasis on additional methods to evolutionary game theory, clearer empirical predictions, and a broader consideration of cultural transmission. © 2007 Cambridge University Press.
Abstract.
Mesoudi A (2007). Has mental time travel really affected human culture?.
Behavioral and Brain Sciences,
30(3), 326-327.
Abstract:
Has mental time travel really affected human culture?
Suddendorf & Corballis (S&C) claim that mental time travel has significantly affected human cultural change. This echoes a common criticism of theories of Darwinian cultural evolution: that, whereas evolution is blind, culture is directed by people who can foresee and plan for future events. Here I argue that such a claim is premature, and more rigorous tests of S&C's claim are needed. © 2007 Cambridge University Press.
Abstract.
2006
Mesoudi A, Whiten A, Dunbar R (2006). A bias for social information in human cultural transmission.
Br J Psychol,
97(Pt 3), 405-423.
Abstract:
A bias for social information in human cultural transmission.
Evolutionary theories concerning the origins of human intelligence suggest that cultural transmission might be biased toward social over non-social information. This was tested by passing social and non-social information along multiple chains of participants. Experiment 1 found that gossip, defined as information about intense third-party social relationships, was transmitted with significantly greater accuracy and in significantly greater quantity than equivalent non-social information concerning individual behaviour or the physical environment. Experiment 2 replicated this finding controlling for narrative coherence, and additionally found that information concerning everyday non-gossip social interactions was transmitted just as well as the intense gossip interactions. It was therefore concluded that human cultural transmission is biased toward information concerning social interactions over equivalent non-social information.
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Mesoudi A, Whiten A, Laland KN (2006). A science of culture: Clarifications and extensions.
Behavioral and Brain Sciences,
29(4), 366-383.
Abstract:
A science of culture: Clarifications and extensions
We are encouraged that the majority of commentators endorse our evolutionary framework for studying culture, and several suggest extensions. Here we clarify our position, dwelling on misunderstandings and requests for exposition. We reiterate that using evolutionary biology as a model for unifying the social sciences within a single synthetic framework can stimulate a more progressive and rigorous science of culture. © 2006 Cambridge University Press.
Abstract.
Mesoudi A, Whiten A, Laland KN (2006). Towards a unified science of cultural evolution.
Behav Brain Sci,
29(4), 329-347.
Abstract:
Towards a unified science of cultural evolution.
We suggest that human culture exhibits key Darwinian evolutionary properties, and argue that the structure of a science of cultural evolution should share fundamental features with the structure of the science of biological evolution. This latter claim is tested by outlining the methods and approaches employed by the principal subdisciplines of evolutionary biology and assessing whether there is an existing or potential corresponding approach to the study of cultural evolution. Existing approaches within anthropology and archaeology demonstrate a good match with the macroevolutionary methods of systematics, paleobiology, and biogeography, whereas mathematical models derived from population genetics have been successfully developed to study cultural microevolution. Much potential exists for experimental simulations and field studies of cultural microevolution, where there are opportunities to borrow further methods and hypotheses from biology. Potential also exists for the cultural equivalent of molecular genetics in "social cognitive neuroscience," although many fundamental issues have yet to be resolved. It is argued that studying culture within a unifying evolutionary framework has the potential to integrate a number of separate disciplines within the social sciences.
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Author URL.
2004
Mesoudi A, Whiten A, Laland KN (2004). Perspective: is human cultural evolution Darwinian? Evidence reviewed from the perspective of the Origin of Species.
Evolution,
58(1), 1-11.
Abstract:
Perspective: is human cultural evolution Darwinian? Evidence reviewed from the perspective of the Origin of Species.
The claim that human culture evolves through the differential adoption of cultural variants, in a manner analogous to the evolution of biological species, has been greeted with much resistance and confusion. Here we demonstrate that as compelling a case can now be made that cultural evolution has key Darwinian properties, as Darwin himself presented for biological evolution in the Origin of Species. Culture is shown to exhibit variation, competition, inheritance, and the accumulation of successive cultural modifications over time. Adaptation, convergence, and the loss or change of function can also be identified in culture. Just as Darwin knew nothing of genes or particulate inheritance, a case for Darwinian cultural evolution can be made irrespective of whether unitary cultural replicators exist or whether cultural transmission mechanisms are well understood.
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Mesoudi A, Whiten A (2004). The hierarchical transformation of event knowledge in human cultural transmission.
Journal of Cognition and Culture,
4(1), 1-24.
Abstract:
The hierarchical transformation of event knowledge in human cultural transmission
There is extensive evidence that adults, children, and some non-human species, represent routine events in the form of hierarchically structured 'action scripts,' and show superior recall and imitation of information at relatively high-levels of this hierarchy. Here we investigate the hypothesis that a 'hierarchical bias' operates in human cultural transmission, acting to impose a hierarchical structure onto descriptions of everyday events, and to increasingly describe those events in terms of higher hierarchical levels. Descriptions of three everyday events (going to a restaurant, getting up and going shopping) expressed entirely in terms of basic low-level actions were transmitted along ten chains each containing four adult human participants. It was found that the proportion of low-level information showed a significant linear decrease with transmission generation, while the proportions of medium- and high-level information showed significant linear increases, consistent with the operation of a hierarchical bias. The findings additionally provide support for script theory in general, and are discussed in relation to hierarchical imitation in non-human primates. © Koninklijke Brill, Leiden 2004.
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