Kevin N. Laland

Social learning strategies

In most studies of social learning in animals, no attempt has been made to examine the nature of the strategy adopted by animals when they copy others. Researchers have expended considerable effort in exploring the psychological processes that underlie social learning and amassed extensive data banks recording purported social learning in the field, but the contexts under which animals copy others remain unexplored. Yet, theoretical models used to investigate the adaptive advantages of social learning lead to the conclusion that social learning cannot be indiscriminate and that individuals should adopt strategies that dictate the circumstances under which they copy others and from whom they learn. In this article, I discuss a number of possible strategies that are predicted by theoretical analyses, includingcopy when uncertain,copy the majority, andcopy if better, and consider the empirical evidence in support of each, drawing from both the animal and human social learning literature. Reliance on social learning strategies may be organized hierarchically, their being employed by animals when unlearned and asocially learned strategies prove ineffective but before animals take recourse in innovation.

Niche construction, biological evolution, and cultural change

We propose a conceptual model that maps the causal pathways relating biological evolution to cultural change. It builds on conventional evolutionary theory by placing emphasis on the capacity of organisms to modify sources of natural selection in their environment (niche construction) and by broadening the evolutionary dynamic to incorporate ontogenetic and cultural processes. In this model, phenotypes have a much more active role in evolution than generally conceived. This sheds light on hominid evolution, on the evolution of culture, and on altruism and cooperation. Culture amplifies the capacity of human beings to modify sources of natural selection in their environments to the point where that capacity raises some new questions about the processes of human adaptation.

How culture shaped the human genome: bringing genetics and the human sciences together

Researchers from diverse backgrounds are converging on the view that human evolution has been shaped by gene–culture interactions. Theoretical biologists have used population genetic models to demonstrate that cultural processes can have a profound effect on human evolution, and anthropologists are investigating cultural practices that modify current selection. These findings are supported by recent analyses of human genetic variation, which reveal that hundreds of genes have been subject to recent positive selection, often in response to human activities. Here, we collate these data, highlighting the considerable potential for cross-disciplinary exchange to provide novel insights into how culture has shaped the human genome.

Why copy others? Insights from the social learning strategies tournament.

It Pays to Be a Copy Cat Does it pay to copy what others do? Rendell et al. (p. 208) elected to copy Robert Axelrods 1979 tournament in which strategies for playing the iterated prisoners dilemma game were pitted against each other until an overall winner emerged—the tit-for-tat strategy. In the 2008 tournament, 100 social learning strategies designed to cope with a changing environment competed against each other; the winning strategy involved sampling the behaviors of other players periodically, rather than exploring the environment alone. Learning from what others do is more efficient than learning all on one’s own. Social learning (learning through observation or interaction with other individuals) is widespread in nature and is central to the remarkable success of humanity, yet it remains unclear why copying is profitable and how to copy most effectively. To address these questions, we organized a computer tournament in which entrants submitted strategies specifying how to use social learning and its asocial alternative (for example, trial-and-error learning) to acquire adaptive behavior in a complex environment. Most current theory predicts the emergence of mixed strategies that rely on some combination of the two types of learning. In the tournament, however, strategies that relied heavily on social learning were found to be remarkably successful, even when asocial information was no more costly than social information. Social learning proved advantageous because individuals frequently demonstrated the highest-payoff behavior in their repertoire, inadvertently filtering information for copiers. The winning strategy (discountmachine) relied nearly exclusively on social learning and weighted information according to the time since acquisition.

Cognitive culture: theoretical and empirical insights into social learning strategies

Research into social learning (learning from others) has expanded significantly in recent years, not least because of productive interactions between theoretical and empirical approaches. This has been coupled with a new emphasis on learning strategies, which places social learning within a cognitive decision-making framework. Understanding when, how and why individuals learn from others is a significant challenge, but one that is critical to numerous fields in multiple academic disciplines, including the study of social cognition.

Cause and Effect in Biology Revisited: Is Mayr’s Proximate-Ultimate Dichotomy Still Useful?

Fifty years ago, Ernst Mayr published a hugely influential paper on the nature of causation in biology, in which he distinguished between proximate and ultimate causes. Mayr equated proximate causation with immediate factors (for example, physiology) and ultimate causation with evolutionary explanations (for example, natural selection). He argued that proximate and ultimate causes addressed different questions and were not alternatives. Mayr’s account of causation remains widely accepted today, with both positive and negative ramifications. Several current debates in biology (for example, over evolution and development, niche construction, cooperation, and the evolution of language) are linked by a common axis of acceptance/rejection of Mayr’s model of causation. We argue that Mayr’s formulation has acted to stabilize the dominant evolutionary paradigm against change but may now hamper progress in the biological sciences.

Shoaling generates social learning of foraging information in guppies

Two experimental studies are reported which investigate the social learning of foraging information in guppies, Poecilia reticulataIn both cases, untrained adult female guppies swam with trained conspecifics to feed, and in the process learned a route to a food source. In experiment 1, subjects were given 5 days experience swimming with demonstrator fish trained to take one of two equivalent routes to food. When tested alone, subjects preferentially used the route of their demonstrators. Experiment 2 investigated whether this social learning could mediate the stable transmission of route preferences among small populations of fish. This experiment used a transmission chain design, in which fish in small founder populations were trained to take one of the two routes, with founder members gradually replaced by untrained conspecifics. Three days after all founder members had been removed, populations of untrained fish still maintained strong preferences for the routes of their founders. The results suggest that the tendency to shoal may facilitate a simple form of guided social learning, which allows guppies to learn about their local environments. They also imply that selectively neutral behavioural alternatives may be maintained as traditions in aggregated animal populations by very simple social mechanisms. The transmission chain method may be particularly useful for studying social species, such as the guppy, that do not respond well to isolation testing.

Gene-culture coevolutionary theory

Gene-culture coevolutionary theory is a branch of theoretical population genetics that models the transmission of genes and cultural traits from one generation to the next, exploring how they interact. These models have been employed to examine the adaptive advantages of learning and culture, to investigate the forces of cultural change, to partition the variance in complex human behavioral and personality traits, and to address specific cases in human evolution in which there is an interaction between genes and culture.

Fish cognition and behavior

The field of animal cognition is the modern approach to understanding the mental capabilities of animals. The theories are largely an extension of early comparative psychology with a strong influence of behavioural ecology and ethology. Cognition has been variously defined in the literature. Some researchers confine cognition to higher order mental functions including awareness, reasoning and consciousness. However, a more general definition of cognition also includes perception, attention, memory formation and executive functions related to information processing such as learning and problem solving. The study of animal cognition has been largely confined to birds and mammals, particularly non-human primates. This bias in the literature is in part due to the approach taken in the 1950s when cognitive psychologists began to compare known human mental processes with other closely related species. This bias was reinforced by an underlying misconception that learning played little or no role in the development of behaviour in reptiles and fishes. Throughout scientific history fishes have largely been viewed as automatons. Their behaviour was thought to be almost exclusively controlled by unlearned predispositions. Ethologists characterised their behaviour as a series of fixed action patterns released on exposure to appropriate environmental cues (sign stimuli). Whilst there is no doubt that fishes are the most ancient form of vertebrates, they are only ‘primitive’ in the sense that they have been on earth for in excess of 500 million years and that all other vertebrates evolved from some common fish-like ancestor (around 360 million years ago). However, it is important to note that fishes have not been stuck in an evolutionary quagmire during this time. Their form and function have not remained stagnant over the ages. On the contrary, within this time frame they have diversified immensely to the point where there are more species of fish than all other vertebrates combined (currently over 32,000 described species) occupying nearly every imaginable aquatic niche. The erroneous view that both behavioural and neural sophistications are associated in a linear progression from fishes through reptiles and birds to mammals is largely due to a heady mix of outdated and unscientific thinking. Aristotle’s concept of Scala naturae

Identification of the Social and Cognitive Processes Underlying Human Cumulative Culture

Acquire and Share Few would argue with the stance that human social cognition supports an unequaled capacity to acquire knowledge and to share it with others. Dean et al. (p. 1114; see the Perspective by Kurzban and Barrett) compared the extent to which these social and cognitive psychological processes can be elicited in children, capuchins, and chimpanzees through the use of a three-level puzzlebox task. Incentivized by improving rewards, 3- to 4-year-old children progressed from the first to the third level by imitating observed actions, taught other members of their social group how to solve the problem, and shared the rewards obtained. By contrast, neither the capuchins nor chimpanzees, very few of which ever reached the third level, exhibited these charactertistics. Humans not only watch and imitate each other but also learn from each other in multiple ways. The remarkable ecological and demographic success of humanity is largely attributed to our capacity for cumulative culture, with knowledge and technology accumulating over time, yet the social and cognitive capabilities that have enabled cumulative culture remain unclear. In a comparative study of sequential problem solving, we provided groups of capuchin monkeys, chimpanzees, and children with an experimental puzzlebox that could be solved in three stages to retrieve rewards of increasing desirability. The success of the children, but not of the chimpanzees or capuchins, in reaching higher-level solutions was strongly associated with a package of sociocognitive processes—including teaching through verbal instruction, imitation, and prosociality—that were observed only in the children and covaried with performance.