Dr Tim W. Fawcett - Anticipating the future: evolutionary explanations for risk sensitivity, contrast effects and animal play

Animals live in a world that is complex and uncertain, but not completely unpredictable. Natural environments typically have the property of temporal autocorrelation, which means that current conditions provide information about conditions in the near future. We should expect natural selection to have favoured animals with decision rules that exploit this statistical structure, adjusting their behaviour adaptively in response to information about future conditions. In this talk I will consider three contexts in which this perspective can help us to understand otherwise puzzling forms of behaviour. I will first discuss the fourfold pattern of risk sensitivity, which is a famous result from studies of human decision making. I will then explore the evolution of contrast effects, a taxonomically widespread phenomenon in which the response to current conditions depends on conditions experienced in the recent past. Finally I will discuss winner and loser effects and the evolution of play-fighting, which is a long-standing puzzle in behavioural biology. In all of these cases, seemingly irrational behaviour can arise from adaptive information use in a temporally autocorrelated environment.