The Affect System

The affect system refers to the functional components involved in appetitive and aversive information processing. We review evidence suggesting that affect is not a unitary faculty but rather is composed of a number of distinct processes. Physical limitations constrain behavioral expressions and incline behavioral predispositions toward a bipolar (good-bad, approach-withdraw) organization, but this organization appears to be the consequence of multiple operations, including the activation of positivity (appetition) and the activation of negativity (aversion), at earlier affective-processing stages. The partial segregation of positive and negative affective processing afforded evolution the opportunity to sculpt distinctive activation functions for these affective components and allows their coactivation. Coactivation, in turn, cultivates the exploration of novel environments and the pursuit of seemingly hospitable events while fostering vigilance for and rapid retreats from hostile developments.