Stable social groups foster conformity and among-group differences

The social niche hypothesis theorizes that repeated social interactions between group members is an important mechanism for generating consistent individual differences in behaviour. However, such frequent interactions also have the potential to mask or suppress behavioural differences if individuals conform towards a group behavioural norm (i.e. the social conformity) by either synchronizing their behaviour or shifting their behaviour towards that of influential group members. Both of these predictions hinge on the notion that social feedback among group members plays a key role in modulating consistent behavioural variation, thus in the absence of such feedback, it could be expected that such consistent variation will be reduced. Here, we investigated how a one-month housing with a stable social group, as opposed to being socially isolated, affected consistent individual differences in the shoaling tendencies of stickleback (Gasterosteus aceluteus). Specifically, we repeatedly tested ...