invariably affect the size of one’s pupils. Neurophysiological factors and chemical stimulants or depressants are known to affect pupil size as well. Nevertheless, research has provided some interesting findings that may have implications for social interactions (Bakan, 1971; Burkhardt, Weider-Hatfield, & Hocking, 1985; Exline & Winters, 1965; Exline, Gray, & Schuette, 1965; Hess, 1965; Hess & Polt, 1960; Hess, Seltzer, & Schlien, 1965; Hindmarch, 1970; Hood, Willen, & Driver, 1998; Scherwitz & Helmreich, 1973; Vlietstra & Manske, 1981; Richmond, 2002).Researchers were interested in the effects of certain visual stimuli on pupil size. They found that men’s pupils dilated when they viewed posters of women, and women’s pupils dilated when they observed photographs of men. Another study found that the pupils of gay men dilated when they were shown photographs of men. Still another study found that women’s pupils dilated when they were shown photographs of newborn infants.These studies suggest that pupil dilation may be a good indication of positive emotional arousal and interest in what is being observed. Pupil constriction, on the other hand, seems to indicate an aversion to the thing or person being observed. Thus, it is not too great a leap to speculate that if we see that the eyes are dilated in the person with whom we are talking, it may be a sign that that person is interested in what we are saying or even in us.Indeed, 1 study found that dilated pupils in photographs of women enhanced perceptions of attractiveness. Long before this research, several 100 years ago, women used the drug belladonna to cause their pupils to dilate. (This is essentially the same drug eye doctors use during examinations today to dilate our pupils.) Dilated pupils, thewomen believed, made them more appealing to men. In the recent study just cited, 2 identical pictures of the same women were used, 1 picture w/ pupils retouched to appear dilated, & the other w/ pupils retouched to appear constricted. Men who evaluated the pictures attributed more positive characteristics to the 1 w/ dilated pupils & more negative characteristics to the 1 with constricted pupils.
An interesting phenomenon that has been discovered in the pupillometric research citedabove is that there tends to be a reciprocal effect on individuals who observe dilated pupils. That is, in viewing the dilated pupils of someone, the viewer’s pupils tend to dilate as well. This seems to suggest that dilated pupils enhance positive responses & create perceptions of attractiveness. Constricted pupils, on the other hand, do not generally elicit positive arousal & may reduce perceptions of attractiveness.As to the importance of pupil dilation in human interaction, we leave the decision up to you. Clearly, it is easier to see dilation in blue-eyed people than in brown-eyed people. You usually cannot see the pupils of another person’s eyes in a context in which emotional reaction is the primary determinant of pupil size; ambient lighting is always a factor. Under controlled conditions, however, it probably is possible to gain some emotional information from this aspect of human eye behavior. At least, that is what