Is the Proust phenomenon fact or fiction? A systematic review and meta-analysis of odor-evoked autobiographical...

Odors are widely believed to be the most powerful trigger for autobiographical memory (AM). This meta-analysis provides the first comprehensive meta-analytic test of this claim, known as the Proust phenomenon. Eighteen experimental/quasi-experimental studies were included in this meta-analysis. Olfactory cueing was compared with a variety of cueing modalities, and seven key characteristics of evoked AMs (specificity, vividness, emotional intensity, pleasantness, rarity, evocativeness, and age of AMs) were assessed. Olfactory cues showed a greater effect (advantage) over other cue types for emotional intensity, pleasantness, evocativeness, and age of AMs. Sample size was negatively associated with effect sizes for emotional intensity, pleasantness, and rarity, although the overall effect for rarity was not significant. Higher proportions of females and more recent publication years were each associated with smaller effects for evocativeness and pleasantness, respectively. Subgroup analyses showed that the advantage of olfactory cues for emotional intensity was stronger in within-subject than between-subject designs. Moreover, their advantage in terms of pleasantness was greatest relative to label cues, followed by visual and auditory cues. Although olfactory cues showed an advantage for four characteristics of AMs, these results do not fully confirm the Proust phenomenon. Overall, these findings suggest that the olfactory advantage is selective rather than universal, and future studies should clarify the conditions under which it emerges.