Summary: McNamara et al. (2013)

Animals are able to evaluate the word in relative terms through successive contrast effects. These behaviours are dependent on the state of the current conditions (better or worse) in relation to previous conditions. Generally, descriptive models of various processes (psychological and physiological) attempt to explain these effects. The factors promoting the evolution of these contrast effects has been relatively poorly studied. McNamara et al. (2013) used simple and general optimality models to show that adaptive responses to uncertainty result in contrast effects in an environment that is dynamic and unpredictable. They suggest that sensitivity to past conditions will be selected for by a wide range of environmental change patterns, which can generate either positive or negative contrast effects. Based on these findings, McNamara et al. (2013) they suggest that environmental stochasticity and uncertainty should be included into future adaptive behaviour models.