This paper proposes that human expression of pain in the presence or absence of caregivers, and the detection of pain by observers, arises from evolved propensities. The function of pain is to demand attention and prioritise escape, recovery, and healing; where others can help achieve these goals, effective communication of pain is required. Evidence is reviewed of a distinct and specific facial expression of pain from infancy to old age, consistent across stimuli, and recognizable as pain by observers. Voluntary control (...) over amplitude is incomplete, and observers can better detect pain that the individual attempts to suppress rather than amplify or simulate. In many clinical and experimental settings, the facial expression of pain is incorporated with verbal and nonverbal vocal activity, posture, and movement in an overall category of pain behaviour. This is assumed by clinicians to be under operant control of social contingencies such as sympathy, caregiving, and practical help; thus, strong facial expression is presumed to constitute an attempt to manipulate these contingencies by amplification of the normal expression. Operant formulations support skepticism about the presence or extent of pain, judgments of malingering, and sometimes the withholding of caregiving and help. To the extent that pain expression is influenced by environmental contingencies, however, could equally plausibly constitute the release of suppression according to evolved contingent propensities that guide behaviour. Pain has been largely neglected in the evolutionary literature and the literature on expression of emotion, but an evolutionary account can generate improved assessment of pain and reactions to it. (shrink)

Although torture can establish guilt through confession, how are judgments of guilt made when tortured suspects do not confess? We suggest that perceived guilt is based inappropriately upon how much pain suspects appear to suffer during torture. Two psychological theories provide competing predictions about the link between pain and perceived blame: cognitive dissonance, which links pain to blame, and moral typecasting, which links pain to innocence. We hypothesized that dissonance might characterize the relationship between torture and blame for those close (...) to the torture, while moral typecasting might characterize this relationship for those more distant from it. Accordingly, this experiment placed participants into one of two different roles in which people may be exposed to torture. Participants in the proximal role of prison staffer saw suffering torture victims as relatively more guilty, while participants in the relatively distant role of a radio listener saw suffering victims as more innocent. (shrink)