Is a generalized positive incentive motivation a construct appropriate to the human level of behavior or would sensation or novelty seeking be a more appropriate one? Is positive incentive motivation, or susceptibility to signals of reward, a mechanism related only to extraversion traits including sociability, activation, social potency, and positive affect? Research shows that susceptibility to reward is related to impulsive sensation seeking and aggression as well as sociability and an aroused type of positive affect. Comparative and indirect human correlates suggest an involvement of dopaminergic reactivity in sensation seeking and sociability.