Animal personality and behavioural syndromes

Abstract

Behaviours are considered to be among the most flexible traits in animals and often reflect conditional responses upon the behaviours of others, or to changing environmental conditions. However, in contrast to the presumed advantages of behavioural flexibility, individuals within the same species or populations often consistently differ in their behaviour, that is, some individuals are consistently more aggressive, more explorative, or shyer than others. This phenomenon has been termed ‘animal personality’ or a ‘behavioural syndrome’. This chapter gives an overview about the current state of research in the field of animal personality by summarising the evolutionary concepts that have been put forward to explain the three questions arising from the phenomenon, i.e. why individuals are consistent in their behaviour, why there are individual differences in behaviour and why behavioural traits are sometimes correlated among each other. It has been shown that animal personality is heritable and entails fitness consequences, which demonstrates that it is subject to evolutionary processes. Moreover, as consistent individual differences in behaviour can result from developmental processes, research on animal personality integrates proximate and functional questions about animal behaviour. Therefore, animal personality research provides an integrative approach to understand animal behaviour by taking into account the causes and potential effects of intrinsic individual differences in behaviour.