Context congruence: How associative learning modulates cultural evolution.

The adoption of cultural variants by learners is affected by multiple factors including the prestige of the model and the value and frequency of different variants. However, little is known about what affects onward cultural transmission, or the choice of variants that models produce to pass on to new learners. This study investigated the effects on this choice of congruence between two contexts: the one in which variants are learned and the one in which they are later transmitted on.

Percolation through Voids around Randomly Oriented Polyhedra and Axially Symmetric Grains.

Porous materials made up of impermeable grains constrain fluid flow to voids around the impenetrable inclusions. A percolation transition marks the boundary between densities of grains permitting bulk transport and concentrations blocking traversal on macroscopic scales. With dynamical infiltration of void spaces using virtual tracer particles, we treat inclusion geometries exactly.

Innovation and social transmission in experimental micro-societies: exploring the scope of cumulative culture in young children.

The experimental study of cumulative culture and the innovations essential to it is a young science, with child studies so rare that the scope of cumulative cultural capacities in childhood remains largely unknown. Here we report a new experimental approach to the inherent complexity of these phenomena. Groups of 3-4-year-old children were presented with an elaborate array of challenges affording the potential cumulative development of a variety of techniques to gain increasingly attractive rewards.

Young children display an increase in prosocial donating in response to an upwards shift in generosity by a same-aged peer.

Adult humans frequently engage in the reciprocal exchange of resources with other individuals. However, despite the important role that reciprocity plays in maintaining co-operative exchange we know relatively little of when, and how, reciprocity develops. We first asked whether pairs of young children (M = 74 months) would engage in direct reciprocity in a 'prosocial choice test' where a donor could select either a higher, or a lower, value reward (1v 2) for a partner at no cost to themselves (1v 1).

The Effect of Dog-Assisted Intervention on Student Well-Being, Mood, and Anxiety.

This novel, exploratory study investigated the effect of a short, 20 min, dog-assisted intervention on student well-being, mood, and anxiety. One hundred and thirty-two university students were allocated to either an experimental condition or one of two control conditions. Each participant completed the Warwick-Edinburgh Mental Well-Being Scale (WEMBS), the State Trait Anxiety Scale (STAI), and the UWIST Mood Adjective Checklist (UMACL) both before, and after, the intervention.

Is the tendency to conform influenced by the age of the majority?

The aim of the current study was to explore the influence that the age and the familiarity of a group majority has on copying fidelity in 4- to 6-year-old children. In Experiment 1, participants (N=120, M=68months) viewed five child models, all of whom were either younger than, the same age as, or older than themselves, open a puzzle box using an inefficient technique (four models) or an efficient technique (one model). In Experiment 2 (N=82, M=71months), the identical task was presented by groups of unfamiliar models.

The Development of Selective Copying: Children's Learning From an Expert Versus Their Mother.

This study tested the prediction that, with age, children should rely less on familiarity and more on expertise in their selective social learning. Experiment 1 (N = 50) found that 5- to 6-year-olds copied the technique their mother used to extract a prize from a novel puzzle box, in preference to both a stranger and an established expert. This bias occurred despite children acknowledging the expert model's superior capability.

Do Children Copy an Expert or a Majority? Examining Selective Learning in Instrumental and Normative Contexts.

This study examined whether instrumental and normative learning contexts differentially influence 4- to 7-year-old children's social learning strategies; specifically, their dispositions to copy an expert versus a majority consensus. Experiment 1 (N = 44) established that children copied a relatively competent "expert" individual over an incompetent individual in both kinds of learning context. In experiment 2 (N = 80) we then tested whether children would copy a competent individual versus a majority, in each of the two different learning contexts.

Social Learning in the Real-World: 'Over-Imitation' Occurs in Both Children and Adults Unaware of Participation in an Experiment and Independently of Social Interaction.

The current study avoided the typical laboratory context to determine instead whether over-imitation-the disposition to copy even visibly, causally unnecessary actions-occurs in a real-world context in which participants are unaware of being in an experiment. We disguised a puzzle-box task as an interactive item available to the public within a science engagement zone of Edinburgh Zoo. As a member of the public approached, a confederate acting as a zoo visitor retrieved a reward from the box using a sequence of actions containing both causally relevant and irrelevant elements.

"Model age-based" and "copy when uncertain" biases in children's social learning of a novel task.

Theoretical models of social learning predict that individuals can benefit from using strategies that specify when and whom to copy. Here the interaction of two social learning strategies, model age-based biased copying and copy when uncertain, was investigated. Uncertainty was created via a systematic manipulation of demonstration efficacy (completeness) and efficiency (causal relevance of some actions).

Does the Age and Familiarity of the Informant Group Influence the Tendency of 3- and 4-year-old Children to Conform?

The authors' aim was to explore whether the age and the familiarity of the individuals comprising a group majority influenced the tendency of 3- and 4-year-old children to conform. Participants were presented with 2 variants of a novel task in which they were required to judge which of 3 line-drawn tigers had the greatest number of stripes. The participants made their judgments in 2 contexts, first after viewing 5 informants perform the task incorrectly, and second without viewing the responses of other individuals.

The Influence of Receiver Status on Donor Prosociality in 6- to 11-Year-Old Children.

The aim of this study was to explore the interplay between donor prosociality and receiver status using a fixed-choice resource distribution paradigm. Sixty children aged 6-11 years allocated resources to two high-status adults and two lower status adults under three different payoff structures. The donor could choose between an egalitarian option and an option that either resulted in an allocation that favored either the donor (Prosocial) or the receiver (Envy), or one in which the donor sacrificed resources to maintain parity (Costly Sharing).

The influence of peers on the tendency of 3- and 4-year-old children to over-imitate.

Human children have frequently been shown to be high-fidelity imitators who faithfully reproduce the actions performed by a model. Curiously, children do not always appear to copy actions rationally and often copy in situations where doing so will lead to a reduction in task efficiency. This over-imitative tendency has been explored extensively with respect to adult models, but we know very little of the influence that peers can have on the fidelity of copying behavior.

Selective and contagious prosocial resource donation in capuchin monkeys, chimpanzees and humans.

Prosocial acts benefitting others are widespread amongst humans. By contrast, chimpanzees have failed to demonstrate such a disposition in several studies, leading some authors to conclude that the forms of prosociality studied evolved in humans since our common ancestry. However, similar prosocial behavior has since been documented in other primates, such as capuchin monkeys.

Information transmission in young children: when social information is more important than nonsocial information.

The authors' aim was to use a highly novel open diffusion paradigm to investigate the transmission of social information (i.e., gossip) and general knowledge within 2 groups of 10- and 11-year-old children.

The influence of model status on the tendency of young children to over-imitate.

The current study aimed to integrate the trust and over-imitation literatures by allowing groups of 5-year-old children to view one of four adult models, differing in their level of status (high or low), retrieve a reward from inside a transparent puzzle box. Each of the models performed a sequence of tool actions on the box before retrieving the reward. These actions varied according to their causal necessity, with some of the actions being causally necessary for reward retrieval and others being causally irrelevant.

Is the cultural transmission of irrelevant tool actions in adult humans (Homo sapiens) best explained as the result of an evolved conformist bias?

Background: Recent studies of social learning have revealed that adult humans are "over-imitators" who frequently reproduce a model's causally irrelevant tool actions to the detriment of task efficiency. At present our knowledge of adult over-imitation is limited to the fact that adults do over-imitate, we know very little about the causes of this behavior. The current study aimed to provide novel insights into adult over-imitation by extending a paradigm recently used with human children to explore social aspects of over-imitation.

The role of transmission biases in the cultural diffusion of irrelevant actions.

This study used a diffusion chain paradigm to explore the cultural transmission of causally irrelevant tool actions in chains of adult participants. Each chain witnessed an "expert" adult retrieve a reward from inside a puzzle box using a combination of causally relevant actions and causally irrelevant actions. Which of the actions were causally relevant was evident in two of the chains where a transparent box was used.

From over-imitation to super-copying: adults imitate causally irrelevant aspects of tool use with higher fidelity than young children.

Recent research has revealed a striking tendency in young children to imitate even causally irrelevant actions, a phenomenon dubbed 'over-imitation'. To investigate whether children develop beyond this, we allowed both adults and children to witness either a child or adult model performing goal-relevant and goal-irrelevant actions to extract a reward from a transparent puzzle box. Surprisingly, copying of irrelevant actions increased with age, with the adults performing the task with less efficiency than the children.

Does the direction in which a figure is looking influence whether it is visible?

Previous studies have shown that young preschool children are highly sensitive to mutual engagement and struggle to diagnose the visibility of a figure when their facial area is occluded. The present study aimed to explore the specificity of engagement by varying (a) the orientation of a figure relative to an observer and (b) the visible area of the figure's body. Results indicated that young children are sensitive to the orientation of the figure and the presence of a salient barrier over the figure's eyes.

Emulation and "overemulation" in the social learning of causally opaque versus causally transparent tool use by 23- and 30-month-olds.

We explored whether a rising trend to blindly "overcopy" a model's causally irrelevant actions between 3 and 5 years of age, found in previous studies, predicts a more circumspect disposition in much younger children. Children between 23 and 30 months of age observed a model use a tool to retrieve a reward from either a transparent or opaque puzzle box. Some of the tool actions were irrelevant to reward retrieval, whereas others were causally necessary.

Emulation, imitation, over-imitation and the scope of culture for child and chimpanzee.

We describe our recent studies of imitation and cultural transmission in chimpanzees and children, which question late twentieth-century characterizations of children as imitators, but chimpanzees as emulators. As emulation entails learning only about the results of others' actions, it has been thought to curtail any capacity to sustain cultures. Recent chimpanzee diffusion experiments have by contrast documented a significant capacity for copying local behavioural traditions.