Flexibility in behavior is advantageous for organisms that transition between stages of a complex life history. However, various constraints can set limits on plasticity, giving rise to the existence of personalities that have associated costs and benefits. Here, we document a field and laboratory experiment that examines the consistency of measures of boldness, activity, and aggressive behavio...

Animals do not behave in exactly the same way when repeatedly tested in the same context or situation, even once systematic variation, such as habituation, has been controlled for. This unpredictability is called intraindividual variability (IIV) and has been little studied in animals. Here we investigated how IIV in boldness (estimated by flight initiation distances) changed across two seasons...

Personality, the presence of persistent behav105ioral differences among individuals over time or contexts, potentially has important ecological and evolutionary consequences. However, a lack of knowledge about its genetic architecture limits our ability to understand its origin, evolution, and maintenance. Here, we report on a genome-wide quantitative trait locus (QTL) analysis for two personal...

Reintroduction projects may fail because captive-reared animals do not possess the behavioural skills required for survival in the wild. Rearing captive-bred animals in semi-natural enclosures prior to release has been used to improve the survival of reintroduced endangered species, but it is unclear how rearing environment influences the development of behaviour. This study examined the effect...

It has been recognised for some years that animals differ consistently in various aspects of their behaviour, a phenomenon that has come to be referred to as animal personality. Recent work has attempted to investigate the ecological factors that shape personality, including the forms of stress that affect its expression. One of these – disease – is known to exert a considerable effect on host ...

Individuals' access to social information can depend on their social network. Homophily-a preference to associate with similar phenotypes-may cause assortment within social networks that could preclude information transfer from individuals who generate information to those who would benefit from acquiring it. Thus, understanding phenotypic assortment may lead to a greater understanding of the f...

Individual variation in behaviour within populations may be explained in part by demographics and longterm, stable individual psychological differences. We examined the relation between boldness (taken as the time to emerge from a shelter and explore a novel environment) and body size in eight populations of the poeciliid Brachyraphis episcopi originating from sites upstream and downstream of w...

Whether individual behavior in social settings correlates with behavior when individuals are alone is a fundamental question in collective behavior. However, evidence for whether behavior correlates across asocial and social settings is mixed, and no study has linked observed trends with underlying mechanisms. Consistent differences between individuals in boldness, which describes willingness t...

Social animals must time and coordinate their behaviour to ensure the benefits of grouping, resulting in collective movements and the potential emergence of leaders and followers. However, individuals often differ consistently from one another in how they cope with their environment, a phenomenon known as animal personality, which may affect how individuals use coordination rules and requiring ...

Although psychopathic personality (psychopathy) is marked largely by maladaptive traits (e.g., poor impulse control, lack of guilt), some authors have conjectured that some features of this condition (e.g., fearlessness, interpersonal dominance) are adaptive in certain occupations, including leadership positions. We tested this hypothesis in the 42 U.S. presidents up to and including George W. ...