Evolution of animal personalities

Arising from: M. Wolf, G. S. van Doorn, O. Leimar & F. J. Weissing , 581–584 (2007)10.1038/nature05835 ; Wolf et al. reply Wolf et al.1 propose a model to explain the existence of animal personalities, consistent with behavioural differences among individuals in various contexts2,3,4—their explanation is counter-intuitive and cogent. However, all models have their limits, and the particular life-history requirements of this one may be unclear. Here we analyse their model and clarify its organismal scope.