Do animal personalities emerge?

Abstract

The evolution of animal personalities is a topic of primary importance in behavioural ecology. An intriguing empirical fact is the consistency of animal responses to repeated stresses or threats. Wolf et al. propose an evolutionary model to explain the emergence of consistent personalities. They show that a population dimorphism for an exploration trait implies the existence of behavioural syndromes, such as decreased aggressiveness and the boldness of 'thorough explorers'. This finding helps explain how animal responses can be consistent, despite the seeming advantages of flexible responses. However, we contend that the emergence of a dimorphism depends critically on the intensity of the trade-off between exploration investment and first-year fecundity.