Implicit preferences: the role(s) of familiarity in the structural mere exposure effect

In four experiments using an artificial grammar (AG) learning procedure, the authors examined the links between the "classic" mere exposure effect [heightened affect for previously encountered stimulus items (Bornstein, 1989; Zajonc, 1968)] and the "structural" mere exposure effect [greater hedonic appreciation for novel stimuli that conform to an implicitly acquired underlying rule system (Gordon & Holyoak, 1983)]. After learning, participants: (a) classified stimuli according to whether they conformed to the principles of the grammar and, (b) rated them in terms of how much they liked them. In some experiments unusual and unfamiliar symbols were used to instantiate the AG, in others highly familiar characters were used. In all cases participants showed standard AG learning. However, whether the two exposure effects emerged was dependent on symbol familiarity. Symbols with high a priori familiarity produced a structural mere exposure effect. Moderately familiar symbols produced only the classic, but not the structural, mere exposure effect. Highly unfamiliar symbols produced neither exposure effect. Results are discussed in the context of implicit learning theory and implications for a general theory of aesthetics are presented.