Evolution of Personality Differences

by

Denis Réale, Alexander Weiss

• LAST REVIEWED: 20 January 2022
• LAST MODIFIED: 13 January 2014
• DOI: 10.1093/obo/9780199941728-0047

Introduction

The concept of personality comes from psychology. Although they are various definitions of personality, the most accepted definition in biology is that of individual consistent differences in behavioral traits over time and across situations. Psychologists were originally interested in characterizing these consistent individual differences among people and explaining the underlying proximate mechanisms of such differences, but personality is increasingly of interest to evolutionary biologists, who are studying the ultimate causes of personality differences or the evolutionary processes that can generate and maintain individual personality differences. Studying personality differences from an evolutionary point of view is asking why there is so much variation in behavioral traits among individuals in a population. Does the variation among individuals only reflect noise around an adaptive population value, or is it adaptive? The question can be extended to variation in the same behavior among populations within a species and to variation among species. It is also valuable to examine proximate sources of individual variation: a topic overlapping genetics, endocrinology, neurophysiology, and evolutionary ecology. Interestingly, studying the processes responsible for such limited plasticity and individual variation in personality traits helps one to understand the consequences of individual differences in ecological patterns. Therefore, the development of research on personality is currently stimulating a series of studies on the ecology of individual differences. With the concept of personality differences several traits can no longer be seen as highly plastic as they were long thought to be. For example, behavioral traits may be plastic, but individuals are limited in the range of behavioral variation they can express. For this and other logistic reasons, behavioral and physiological traits have not received the same attention from evolutionary biologists as have morphological or life history traits. With the emergence of studies on the evolutionary ecology of personality differences, behavioral and physiological traits find the recognition that they deserved among evolutionary biologists. Therefore, if one were to ask “what is new with personality?” an answer would probably be the strong power of personality to create links between different and often independent fields of research, as well as to develop comprehensive studies that have to consider the multivariate nature of organisms.

Journals

Personality is a broad field overlapping different domains. Articles on the topic are published in a range of journals in psychology and biology. For this reason, it is not easy to find journals that specifically publish articles on the evolution of personality differences. Contributions to the evolutionary and ecological study of personality are mainly published in Animal Behaviour, Behavioural Ecology, and Proceedings of the Royal Society of London B. In psychology, among others, Journal of Comparative Psychology publishes papers on animal personality including some using an evolutionary approach.

• Animal Behaviour. 1953–.

  Founded in 1953 this journal is a collaboration between the Association for the Study of Animal Behaviour and the Animal Behavior Society. It is one of the leaders in the field. The journal publishes a broad array of articles on topics related to animal behavior.

• Behavioral Ecology. 1990–.

  The journal of the International Society for the Study of Behavioral Ecology has traditionally focused on the functional study of behavior, both theoretical and empirical. Recently the journal has broadened the scope of papers published.

• Journal of Comparative Psychology. 1921–.

  Published by the American Psychological Association, this journal focuses on a range of research on animal learning and behavior. The journal has recently published multiple papers on animal personality.

• Proceedings of the Royal Society of London, Series B, Biological Sciences. 1905–.

  A generalist scientific journal, this journal regularly publishes theoretical and empirical studies on personality in both human and nonhuman animals.