Autonomic specificity and emotion.

Autonomic specificity refers to the notion that emotions can be distinguished in terms of their associated patterns of autonomic nervous system activity. This idea has a long history in psychology, tracing back at least to James's (1884) writings on the nature of emotion. Moreover, it is an idea that has always been shrouded in controversy, attracting many critics along the way (e.g., Cacioppo, Klein, Berntson, & Hatfield, 1993; Cannon, 1927; Schachter & Singer, 1962; Zajonc & McIntosh, 1992). The controversy has been framed by two immoderate assertions: (1) Every emotion is autonomically unique; and (2) every emotion is autonomically the same. The uniqueness assertion is generally associated with Alexander's (1950) psychosomatic hypotheses. The second assertion of sameness arguably finds its clearest statement in Mandler's (1975) writings. Needless to say, these are both statements in extremis, and it would be difficult to find undiluted, unhedged versions of either in the contemporary literature. Nonetheless, they form the two poles around which participants in the debate over autonomic specificity have aggregated over the decades. In my view, both of these assertions are highly dubious. Regarding the first assertion of uniqueness, as I hope this chapter makes clear, it is highly likely that reliable autonomic differences only exist for a small number of emotions. Moreover, where these differences do exist, they are likely to be "prototypical" in nature, with particular occurrences of a given emotion showing variation around these central tendencies. Similarly, there is ample basis for rejecting the second