Perception, expression, and social function of pain: a human ethological view

Pain has important biomedical, socioanthropological, semiotic, and other facets. In this contribution pain and the expression of pain are looked at from the perspective of evolutionary biology, utilizing, among others, cross-cultural data from field work in Melanesia. No other being cares for sick and suffering conspecifics in the way humans do. Notwithstanding aggression and neglect, common in all cultures, human societies can be characterized as empathic, comforting, and promoting the health and sell-being of their members. One important stimulus triggering this caring response in others is the expression of pain. The nonverbal channel of communication, particularly certain universal--i.e., culture-independent facial expressions, gestures, and body postures, convey much of the message from the pain-stricken person to the group. These behaviors signal the person's physical and psychical pain, sadness, grief, and despair in ways very similar to the signs given by infants and small children: the body loses tonus and sinks or drops to the ground, the gestures are those of helplessness. Pain and grief may be so strong that control is lost not only over the body's posture but also over the mind's awareness. In such cases the afflicted person may carry out actions endangering himself or others. In general, these behavior patterns resemble those of infants in situations of distress and danger, and it is not surprising that the response of the members of the group is basically parental: taking care, assisting and consoling. Perceptive and behavioral patterns which developed in the course of avian and mammalian phylogeny to serve the well-being of the young have proven, as was shown by Eibl-Eibesfeldt (1989), to be powerful building blocks for actions in other spheres of human interaction. Love is one such field, the reactions to a conspecific suffering pain is another.