Evidence for strong dissociation between emotion and facial displays: the case of surprise.

Eight experiments examined facial expressions of surprise in adults. Surprise was induced by disconfirming a previously established schema or expectancy. Self-reports and behavioral measures indicated the presence of surprise in most participants, but surprise expressions were observed only in 4%-25%, and most displays consisted of eyebrow raising only; the full, 3-component display was never seen. Experimental variations of surprise intensity, sociality, and duration/complexity of the surprising event did not change these results. Electromyographic measurement failed to detect notably more brow raisings and, in one study, revealed a decrease of frontalis muscle activity in the majority of the participants. Nonetheless, most participants believed that they had shown a strong surprise expression.