The Affect System Has Parallel and Integrative Processing Components Form Follows Function

The affect system has been shaped by the hammer and chisel of adaptation and natural selection such that form follows function. The characteristics of the system thus differ across the nervous system as a function of the unique constraints existent at each level. For instance, although physical limitations constrain behavioral expressions and incline behavioral predispositions toward a bipolar (good—bad, approach—withdraw) organization, these limiting conditions lose their power at the level of underlying mechanisms. According to the authors' model of evaluative space ( J. T. Cacioppo & G. G. Berntson, 1994 ; J. T. Cacioppo, W. L. Gardner, & G. G. Berntson, 1997 ), the common metric governing approach—withdrawal is generally a single dimension at response stages that itself is the consequence of multiple operations, such as the activation function for positivity (appetition) and the activation function for negativity (aversion), at earlier affective processing stages. Affect in personality and social psychology has traditionally been treated as the conscious subjective aspect of an emotion considered apart from bodily changes (e.g., Osgood, Suci, & Tannenbaum, 1957 ; Thurstone, 1931 ). Like the organization and processes underlying the undeniable percept that the sun circles the earth, however, the organization and processes underlying affective experiences may be far subtler than their apparent manifestations might lead one to suspect. Although rich in emotional terms ( Clore, Ortony, & Foss, 1987 ; Frijda, Markam, Sato, & Wiers, 1995 ; Ortony, Clore, & Foss, 1987 ; Russell, 1978 ), language sometimes fails to capture affective experiences–especially intense affective experiences–so metaphors become more likely vehicles for rendering these conscious states of mind ( Fainsilber & Ortony, 1987 ; Hoffman, Waggoner, & Palermo, 1991 ; Ortony & Fainsilber, 1989 ). Affective reports have also long been recognized as subject to a host of motivational influences (e.g., Abelson et al., 1968 ; Brehm, 1956 ) and contextual distortions (e.g., Fabrigar, Visser, & Browne, 1997 ; Irvine, 1995 ; Ostrom & Upshaw, 1968 ; Schwarz & Strack, in press ) as well as being only modestly related to other aspects of affective reactions, such as physiology and behavior (e.g., Cook & Selltiz, 1964 ; Lang, 1971 ; Nisbett & Wilson, 1977 ). Furthermore, recent investigations in personality and social psychology have characterized affect as capable of being elicited quickly, effortlessly, automatically, or even unconsciously, on exposure to the stimulus (e.g., Bargh, Chaiken, Govender, & Pratto, 1992 ; Pratto & John, 1991 ; see Tesser & Martin, 1996 ). Investigations of the structure of affective words and of self-reports of affect are, therefore, important but may be incomplete. Our goal here is to review selective evidence ranging from neural mechanisms to political behavior to explore Journal of Personality and Social Psychology © 1999 by the American Psychological Association May 1999 Vol. 76, No. 5, 839-855 For personal use only--not for distribution. Page 1 of 30 3/15/2002 file://C:\E\Reprints\CGB99.htm some of the properties and features of the system underlying affective appraisals, experiences, and actions. 1 As we will see, the structure of the affect system depends on function, which varies across the level of the nervous system (neuraxis).