It is optimal to be optimistic about survival

Abstract

We investigate the optimal behaviour of an organism that is unable to obtain a reliable estimate of its mortality risk. In this case, natural selection will shape behaviour to be approximately optimal given the probability distribution of mortality risks in possible environments that the organism and its ancestors encountered. The mean of this distribution is the average mortality risk experienced by a randomly selected member of the species. We show that if an organism does not know the exact mortality risk, it should act as if the risk is less than the mean risk. This can be viewed as being optimistic. We argue that this effect is likely to be general.

Heritabilities and co-variation among cognitive traits in red junglefowl

“…Theoretical models predict that judgement biases may constitute stable individual traits [47,49], with a heritable component, and therefore may respond to natural selection [47]. Interestingly, theory predicts that varying selection pressures associated with spatio-temporal environmental heterogeneity may lead to genetically based individual differences in both judgement biases and learning abilities [47,52]. Unpredictable environmental variation may select for either optimism or pessimism, depending on the extent of ecological variability and movements between habitat patches [52], and at the same time favour behavioural flexibility [53].…”

“…Interestingly, theory predicts that varying selection pressures associated with spatio-temporal environmental heterogeneity may lead to genetically based individual differences in both judgement biases and learning abilities [47,52]. Unpredictable environmental variation may select for either optimism or pessimism, depending on the extent of ecological variability and movements between habitat patches [52], and at the same time favour behavioural flexibility [53]. Thus, we may expect covariation between these cognitive domains.…”

An Evolutionary Perspective on Information Processing

“…McNamara, Trimmer, and Houston (, appendix 3) analyze the scenario assuming that at each time step, the animal may see a predator without being killed but that having seen a predator, there is some probability, d , that the animal is killed in that time step. The probability of seeing a predator in a given time step is assumed to depend only on the current location (independent of other time steps), and a predator is assumed to be seen before being killed in a given time step.…”

The relationship between personality and cognitionin the fowl, Gallus gallus

“…Selection for aggression might thus influence other traits, like boldness, and might explain why we sometimes observe apparently maladaptive behaviours. Although, what seem like maladaptive behaviour in the short-term, may have positive implications for fitness in the long-term (McNamara et al 2012).…”

“…In addition, there are other aspects of decision-making, than learning, that can be affected. For example, there are biases in cognitive processes (Sharot et al 2009;Mendl et al 2010;McNamara et al 2012) that might be influenced by personality and/or more temporary emotions (i.e. excitement or sadness, Roelofs et al 2016), a research topic that has received research interest the last couple of years.…”