Conformist social learning inoculates against adverse risk aversion
AbstractGiven the ubiquity of potentially adverse biases incurred by trial-and-error learning, it seems paradoxical that improvements in decision-making performance through conformist social learning, a process widely considered to be bias amplification, still prevail in animal behaviour. Here we show, through model analyses and online experiments with 467 adult human subjects, that conformity can promote favourable risk taking in repeated decision making, even though many individuals are systematically biased towards suboptimal risk aversion owing to the myopia of reinforcement learning. Although positive feedback conferred by conformity could result in suboptimal informational cascades, our dynamic model of behaviour identified a key role for negative feedback that arises when a weak minority influence undermines the inherent behavioural bias. This ‘collective behavioural rescue’, emerging through coordination of positive and negative feedback, highlights a benefit of social learning in a broader range of environmental conditions than previously assumed and resolves the ostensible paradox of adaptive collective flexibility through conformity.