Little is known about the effect of personality traits on learning. Thus the aim of this investigation was to better understand the role of depressive personality traits - primarily self-criticism and approach and inhibition tendencies - in reward and punishment learning. In two studies (Study 1: N = 38; Study 2: N = 100), we used a probabilistic classification task in which participants needed to categorize ambiguous stimuli, and then received probabilistic feedback, according to their choice. In Study 2, we employed a variation of this task with difficult vs. easy contingencies. In both studies we examined the association between performance in the task and approach and avoidance personality traits (BIS/BAS, self-criticism and positive generalization) while controlling for depression and intelligence. Self-criticism and a tendency to generalize positive events were positively associated with reward, but not punishment, learning. As well, after exposure to difficult contingencies, participants had delayed punishment learning. In light of these results, we suggest that self-criticism might enhance monitoring of errors, which improves reward learning.
