Supplementary material from "Lateralization correlates with individual differences in inhibitory control in zebrafish"

Individual fitness often depends on the ability to inhibit behaviours not adapted to a given situation. However, inhibitory control can vary greatly between individuals of the same species. We investigated a mechanism that might maintain this variability in zebrafish. We demonstrate that inhibitory control correlates with cerebral lateralization, the tendency to process information with one brain hemisphere or the other. Individuals that preferentially observed a social stimulus with the right eye and thus processed social information with the left brain hemisphere, inhibited foraging behaviour more efficiently. Therefore, selective pressures that maintain lateralization variability in populations might provide indirect selection for variability in inhibitory control. Our study suggests that cognitive individual differences may result from complex multi-trait selection mechanisms.