Behavioural Dispositions that are individually irrational in the current Environment (due to either random deviation or maladaptation) can improve the chances of a population to adapt to disruptive changes.
In other words, they are necessary ingredients of a population’s rational repertoire of dispositions in complex environments and get selected in these environments.
The rational behavior is a function of the particular environment, and different environments lead to different rational behaviors in evolution. As a result, irrational behaviors not only persist in Evolution, but are also necessary for robust growth of population in stochastic environments.Brennan et al. (2017), 2
- Brennan et al. (2017): “Variety Is the Spice of Life: Irrational Behavior as Adaptation to Stochastic Environments“