The experience of another person is never directly available to us, just as our own experiences cannot be directly experienced by other people. ‘We're all of us sentenced to solitary confinement inside our own skins' (Tennessee Williams). We can use empathy to get closer to another person's experience; in other words we imagine ourselves in the same situation as he is in and credit him with the feelings we would then experience. However, it is invariably our own experience that we use as the yardstick. We judge another person's experience from his behaviour, of which speech is one of the most informative parts. If another person says, ‘I see a man’, and there is indeed a man in our shared visual field, then both of us assume we are sharing a common perceptual experience. When there is no external referent, as in the statement ‘I feel sad’, the assumption of a common experience rests on more tenuous grounds. We can sometimes look to an external situation, like the loss of a close relative, to confirm that we understand the statement in the same way. But on many occasions there is no readily understandable link between a person's mood and the situation in which he finds himself. In judging a person's mood we also depend a great deal on non-verbal accompaniments of emotional states, but these are known to vary from culture to culture and from individual to individual. The movements used to express emotion, particularly those of the face, are so complex that very few attempts have been made to describe and categorize them accurately. There is a paucity of studies of this kind between Charles Darwin's pioneering work of 1872, which attempted to show the similarity of emotional expression throughout the races of mankind, and the recent work of Ekman and Friesen (1968) and Grant (1970). The few systematic studies in the intervening century do not support an invariable pattern of expression accompanying specific emotions. However, Ekman et al. (1969) found that subjects from literate cultures accurately identified emotions from photographs of the face, although subjects from pre-literate cultures showed much less agreement.
Pupillary contagion is independent of the emotional expression of the face.
