Duration neglect in retrospective evaluations of affective episodes.

Two experiments documented a phenomenon of duration neglect in people's global evaluations of past affective experiences. In Study 1, 32 Ss viewed aversive film clips and pleasant film clips that varied in duration and intensity. Ss provided real-time ratings of affect during each clip and global evaluations of each clip when it was over. In Study 2, 96 Ss viewed these same clips and later ranked them by their contribution to an overall experience of pleasantness (or unpleasantness). Experimental Ss ranked the films from memory; control Ss were informed of the ranking task in advance and encouraged to make evaluations on-line. Effects of film duration on retrospective evaluations were small, entirely explained by changes in real-time affect and further reduced when made from memory. Retrospective evaluations appear to be determined by a weighted average of "snapshots" of the actual affective experience, as if duration did not matter.