Erratum to ‘Bateman's principles and human sex roles’

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The origins of language in teaching

Research supported in part by a grant from the John Templeton Foundation.I introduce seven criteria for determining the validity of competing theories for the original function of language. I go on to present a novel explanation that meets all the criteria: language originally evolved to teach kin. I suggest that the use of symbols subsequently generated evolutionary feedback at two levels, in the form of self-modified selection pressures that favored structures in the mind that functioned to manipulate and use symbols with efficiency, and cultural selection on languages for learnability.Publisher PDFPeer reviewe

Environmental complexity influences association network structure and network-based diffusion of foraging information in fish shoals

This project was funded by grants from the Natural Environment Research Council (NE/D010365/1) and the European Research Council (EVOCULTURE 232823) to K.N.L.Socially transmitted information can significantly affect the ways in which animals interact with their environments. We used network-based diffusion analysis, a novel and powerful tool for exploring information transmission, to model the rate at which sticklebacks (Gasterosteus aculeatus) discovered prey patches, comparing shoals foraging in open and structured environments. We found that for groups in the open environment, individuals tended to recruit to both the prey patch and empty comparison patches at similar times, suggesting that patch discovery was not greatly affected by direct social transmission. In contrast, in structured environments we found strong evidence that information about prey patch location was socially transmitted and moreover that the pathway of information transmission followed the shoals' association network structures. Our findings highlight the importance of considering habitat structure when investigating the diffusion of information through populations and imply that association networks take on greater ecological significance in structured than open environments.Publisher PDFPeer reviewe

Familiarity affects social network structure and discovery of prey patch locations in foraging stickleback shoals

Numerous factors affect the fine-scale social structure of animal groups, but it is unclear how important such factors are in determining how individuals encounter resources. Familiarity affects shoal choice and structure in many social fishes. Here, we show that familiarity between shoal members of sticklebacks (Gasterosteus aculeatus) affects both fine-scale social organization and the discovery of resources. Social network analysis revealed that sticklebacks remained closer to familiar than to unfamiliar individuals within the same shoal. Network-based diffusion analysis revealed that there was a strong untransmitted social effect on patch discovery, with individuals tending to discover a task sooner if a familiar individual from their group had previously done so than if an unfamiliar fish had done so. However, in contrast to the effect of familiarity, the frequency with which individuals had previously associated with one another had no effect upon the likelihood of prey patch discovery. This may have been due to the influence of fish on one another's movements; the effect of familiarity on discovery of an empty ‘control’ patch was as strong as for discovery of an actual prey patch. Our results demonstrate that factors affecting fine-scale social interactions can also influence how individuals encounter and exploit resources.Publisher PDFPeer reviewe

Comment concerning cumulative cultural evolution, on M. O'Brien and K.N. Laland 'Genes, culture and agriculture: an example of human niche construction'

O’Brien and Laland point out that human culture is exceptional in its cumulative nature. This is often characterized by the ratchet effect, highlighting that high-fidelity social transmission can underpin the accumulation of trait modifications. They also note that the developmental niche-construction processes underlying cultural evolution are understudied. I agree that the evolutionary consequences of culturally constructed learning environments are indeed understudied and that attention to this area may provide a fresh assessment of cumulative cultural evolution. An important focus of cumulative cultural evolution research is in assessing individual cognitive prerequisites that facilitate high-fidelity cultural transmission and the adoption of adaptive innovations (Ehn and Laland 2012). However, it is also important to consider the role of developmental niche construction and the ecological inheritance of learning environments, including forms of symbolic representation and material culture, on cumulative cultural evolution (Cole 1995; Sterelny 2012; Wheeler and Clark 2009). Culturally derived scaffolding for learning can have a direct effect on the differential adoption and retention of cultural traits (cultural selection). For instance, pedagogical traditions in apprenticeships, including traditional patterns of intervention, correction, and collaboration may influence the fidelity of transmission and the potential for cumulative cultural evolution (Gergely and Csibra 2006; Tehrani and Reide 2008; Tennie, Call, and Tomasello 2009). There is also the potential for cumulative cultural evolutionary dynamics to be shaped by forms of symbolic representation. Mathematical history provides particularly obvious examples, where invention of new notation systems, for instance Hindu-Arabic in place of Roman numerals or Feynman diagrams in quantum mechanics, dramatically altered the evolvability of research fields (Gauvain 1998). Thus, for the cumulative cultural evolution of many traits, high-fidelity social transmission and the potential for invention may be critically affected by culturally constructed learning environments (Tennie, Call, and Tomasello 2009). Furthermore, a complete account of cognition required for cumulative cultural evolution may often be reliant on its extension beyond the mind of the individual and on its distributed nature across people and artefacts (Donald 2000; Hutchins 1995, 2008). Without accounting explicitly for the role of developmental niche construction and the ecological inheritance of learning environments, there can be an over- or misattribution of cognitive facility to the mind in order to explain the cumulative cultural evolution of skills such as computational tasks (Hutchins 1995). O’Brien and Laland provide a detailed account of potential gene-culture coevolutionary pathways affecting the cumulative cultural evolution of farming technologies and medicinal practices. A key process in these dynamics is likely to be the niche construction of inherited learning environments, which themselves can be subject to cultural selection and affected by ecological and genetic evolutionary dynamics of human, crop, livestock, and pathogen populations. Thus, the simple ratchet analogy hides complex mechanisms that can result in cumulative cultural evolution of knowledge and beliefs (Tennie, Call, and Tomasello 2009)

Attentional coordination in demonstrator-observer dyads facilitates learning and predicts performance in a novel manual task

Observational learning is a form of social learning in which a demonstrator performs a target task in the company of an observer, who may as a consequence learn something about it. In this study, we approach social learning in terms of the dynamics of coordination rather than the more common perspective of transmission of information. We hypothesised that observers must continuously adjust their visual attention relative to the demonstrator's time-evolving behaviour to benefit from it. We eye-tracked observers repeatedly watching videos showing a demonstrator solving one of three manipulative puzzles before attempting at the task. The presence of the demonstrator's face and the availability of his verbal instruction in the videos were manipulated. We then used recurrence quantification analysis to measure the dynamics of coordination between the overt attention of the observers and the demonstrator's manipulative actions. Bayesian hierarchical logistic regression was applied to examine (1) whether the observers' performance was predicted by such indexes of coordination, (2) how performance changed as they accumulated experience, and (3) if the availability of speech and intentional gaze of the demonstrator mediated it. Results showed that learners better able to coordinate their eye movements with the manipulative actions of the demonstrator had an increasingly higher probability of success in solving the task. The availability of speech was beneficial to learning, whereas the presence of the demonstrator's face was not. We argue that focusing on the dynamics of coordination between individuals may greatly improve understanding of the cognitive processes underlying social learning

Space-use and sociability are not related to public-information use in ninespine sticklebacks

There has been much recent interest in both public information use, and the evolutionary origins and ecological consequences of animal personalities but surprisingly little integration of these two fields. Personality traits may impact upon the extent to which individuals respond to public information in a number of different ways. As a first step towards addressing some of these questions, in this study, we asked whether personality traits predicted public information use in ninespine sticklebacks (Pungitius pungitius). Over a 33-day period, subjects were scored twice for a number of behavioural traits, including measures of activity, exploration and shoaling tendency, and were exposed multiple times to a public information use foraging task, in which they were required to select the richer of two prey patches based upon the foraging success of two demonstrator groups. The repeatable (r=0.38–0.58) behavioural traits were reduced to two principle components describing space use and sociability. Neither of these was found to be related to either of two measures of public information use. While the personality traits that we considered did not co-vary with public information use in this species, they may well indirectly affect opportunity for exposure to public information, and this is an obvious avenue for further research.PostprintPeer reviewe

The development of adaptive conformity in young children : effects of uncertainty and consensus

Human culture relies on extensive use of social transmission, which must be integrated with independently acquired (i.e. asocial) information for effective decision-making. Formal evolutionary theory predicts that natural selection should favor adaptive learning strategies, including a bias to copy when uncertain, and a bias to disproportionately copy the majority (known as conformist transmission'). Although the function and causation of these evolved strategies has been comparatively well studied, little is known of their development. We experimentally investigated the development of the bias to copy-when-uncertain and conformist transmission in children from the ages of 3 to 7, testing predictions derived from theoretical models. Children first attempted to solve a binary-choice quantity discrimination task themselves using asocial information, but were then given the decisions of informants, and an opportunity to revise their answer. We investigated whether children's revised judgments were adaptively contingent on (i) the difficulty of the trial and (ii) the degree of consensus amongst informants. As predicted, older but not younger children copied others more on more difficult trials than on easier trials, even though older children also showed a tendency to stick with their initial, asocial decision. We also found that older children, like adults, were disproportionately receptive to non-total majorities (i.e. were conformist) whereas younger children were receptive only to total (i.e. unanimous) majorities. We conclude that, whilst the mechanism for incorporating social information into decision-making is initially very blunt, across the course of early childhood it converges on the adaptive learning mechanisms observed in adults and predicted by cultural evolutionary theory. A video abstract of this article can be viewed at http://youtu.be/Qb6JINGYqVkPostprintPeer reviewe

No evidence for individual recognition in threespine or ninespine sticklebacks (Gasterosteus aculeatus or Pungitius pungitius)

Funding UK NERC NE/D010365/1, ERC Advanced Grant EVOCULTURE (232823).Recognition plays an important role in the formation and organization of animal groups. Many animals are capable of class-level recognition, discriminating, for example, on the basis of species, kinship or familiarity. Individual recognition requires that animals recognize distinct cues, and learn to associate these with the specific individual from which they are derived. In this study, we asked whether sticklebacks (Gasterosteus aculeatus and Pungitius pungitius) were capable of learning to recognize individual conspecifics. We have used these fish as model organisms for studying selective social learning, and demonstrating a capacity for individual recognition in these species would provide an exciting opportunity for studying how biases for copying specific individuals shape the dynamics of information transmission. To test for individual recognition, we trained subjects to associate green illumination with the provision of a food reward close to one of two conspecifics, and, for comparison, one of two physical landmarks. Both species were capable of recognizing the rewarded landmark, but neither showed a preference for associating with the rewarded conspecific. Our study provides no evidence for individual recognition in either species. We speculate that the fission–fusion structure of their social groups may not favour a capacity for individual recognition.Publisher PDFPeer reviewe