Absence of a Mere-Exposure Effect in Older and Younger Adults

The mere-exposure effect, in which repeated stimuli are liked more than novel stimuli, is a well-known effect. However, little research has studied adult age differences in mere-exposure effects, despite possible applications in helping older adults transition to new living environments. Here, we report four experiments assessing mere-exposure to neutral-face stimuli in groups of older and younger adult participants tested online. In each experiment, repeated face exposure did not increase liking within either age group; rather, Bayesian evidence favored the null hypothesis of no effect. Older adults reported higher overall liking ratings relative to younger adults, and both groups preferred younger faces, though this tendency was stronger in the younger group. Further exploratory analysis considering factors such as gender or race of the faces and participants did not reveal any consistent results for the mere-exposure effect. We discuss these findings in relation to other recent studies reporting mixed evidence for mere-exposure effects.