Reactive phenotype–social environment correlation, favouring winners over losers, and the magnification of inequality

Experiments in a variety of species including humans have established the ubiquity of winner and loser effects, whereby contest winners are more likely to win future contests, while losers tend to lose future matches. While winner and loser effects, on their own, can establish status inequality, the social environment may also magnify inequality if it anticipates large individual variation and favours winners over losers. To assess this hypothesis, we tested a key assumption and prediction. First, we found that human subjects overestimated individual variation in the two important traits of athleticism and intelligence. Second, we conducted two experiments in which participants read a fictional vignette about either an athletic or academic competition with a clear winner and loser. Participants then had to allocate funds and training between the competitors. In experiment 1, participants allocated more money but not more coaching hours to winners. In experiment 2, participants overwhelmingly allocated a training programme to winners. Our results indicate that there is reactive correlation between phenotypes and their social environment. Such reactive phenotype–social environment correlation may interact with winner and loser effects. This interactive process, which we have termed runaway winner and loser effects, could generate much greater inequality than expected based on the frequently small phenotypic differences between initial winners and losers. • Contest winners tend to win, while losers tend to lose, future matches. • The social environment may treat winners and losers differently. • In two experiments, participants allocated more resources to winners than to losers. • Such social reaction to winners and losers could magnify winner and loser effects.