The behavioural ecology of personality: consistent individual differences from an adaptive perspective

Abstract

Individual humans, and members of diverse other species, show consistent differences in aggressiveness, shyness, sociability and activity. Such intraspecific differences in behaviour have been widely assumed to be non-adaptive variation surrounding (possibly) adaptive population-average behaviour. Nevertheless, in keeping with recent calls to apply Darwinian reasoning to ever-finer scales of biological variation, we sketch the fundamentals of an adaptive theory of consistent individual differences in behaviour. Our thesis is based on the notion that such Ôpersonality differencesÕ can be selected for if fitness payoffs are dependent on both the frequencies with which competing strategies are played and an individual's behavioural history. To this end, we review existing models that illustrate this and propose a game theoretic approach to analyzing personality differences that is both dynamic and state-dependent. Our motivation is to provide insights into the evolution and maintenance of an apparently common animal trait: personality, which has far reaching ecological and evolutionary implications.

Animal personality and state–behaviour feedbacks: a review and guide for empiricists

“…Most of this theory invokes adaptive state-dependent behaviour, explaining personality as an adaptive outcome of among-individual differences in state [11][12][13]. Building on earlier work by Rands et al [14] and Dall et al [15], recent models have focused on the joint emergence and maintenance of among-individual differences in behaviour and state, and how such differences are promoted by positive feedbacks between behaviour and state. These models (both mathematical and verbal) have generated testable predictions for a broad range of scenarios.…”

“…Feedback loops and variation in personalities -the core concept Although behaviour in principle can be infinitely flexible, behavioural repeatability can potentially be explained by among-individual differences in slower-changing or even fixed state variables, in combination with adaptive statedependent behaviour ( [11,12,15,16]; Table 1). Individuals thus differ in behaviour because they differ in state and adjust their behaviour in an adaptive fashion to these differences.…”

Behavioural syndromes, syndrome deviation and the within- and between-individual components of phenotypic correlations: when reality does not meet statistics

“…Dingemanse and Wolf 2010). Although these phenomena are often treated-rather confusingly-as synonymous (Dall et al 2004;Réale et al 2007; Dingemanse et al…”

Diverse societies are more productive: a lesson from ants

“…The concept of personality or behavioural syndromes has re-emerged as a way to study the association of consistent behavioural variants with the reproductive success of animals [1][2][3]. Behavioural syndromes involve: (i) behavioural consistency across time, (ii) consistency of the same behaviour across different contexts, or (iii) correlations of different behaviours [4].…”