Adaptive strategies for managing uncertainty may explain personality-related differences in behavioural plasticity

There is growing evidence that individuals within populations show consistent differences in their behaviour across contexts (personality), and that personality is associated with the extent to which individuals adjust their behaviour as function of changing conditions (behavioural plasticity). We propose an evolutionary explanation for a link between personality and plasticity based upon how individuals manage uncertainty. Individuals can employ three categories of tactics to manage uncertainty. They can 1) gather information (sample) to reduce uncertainty, 2) show strategic (state-dependent) preferences for options that differ in their associated variances in rewards (i.e. variance-sensitivity), or 3) invest in insurance to mitigate the consequences of uncertainty. We explicitly outline how individual differences in the use of any of these tactics can generate personality-related differences in behavioural plasticity. For example, sampling effort is likely to co-vary with individual activity and exploration behaviours, while simultaneously creating population variation in reactions to changes in environmental conditions. Individual differences in the use of insurance may be associated with differences in risk-taking behaviours, such as boldness in the face of predation, thereby influencing the degree of adaptive plasticity across individuals. Population variation in responsiveness to environmental changes may also reflect individual differences in variance-sensitivity, because stochastic change in the environment increases variances in rewards, which may both attract and benefit variance-prone individuals, but not variance-averse individuals. We review the existing evidence that individual variation in strategies for managing uncertainty exist, and describe how positive-feedbacks between sampling, variance-sensitivity and insurance can maintain and exaggerate even small initial differences between individuals in the relative use of these tactics. Given the pervasiveness of the problem of uncertainty, alternative strategies for managing uncertainty may provide a powerful explanation for consistent differences in behaviour and behavioural plasticity for a wide range of traits.