An Assimilative Effect of Stimulus Co-Occurrence on Evaluation Despite Contrasting Relational Information

The co-occurrence of a neutral stimulus with affective stimuli typically causes the neutral stimulus’s evaluation to shift toward the affective stimuli’s valence. Does that assimilative effect occur even when one knows the co-occurrence is due to an opposition relation between the stimuli (e.g., Batman stops crime)? Previous evidence tentatively supported that possibility, based on results compatible with an assimilative effect obscured by a larger contrast effect of the opposition relation (e.g., people like Batman less than expected, perhaps due to his co-occurrence with crime). We report three experiments (N = 802) in which participants preferred stimuli that stopped positive events over stimuli that stopped negative events—an assimilative effect of co-occurrence, unobscured by a contrast effect, despite comprehending the opposition relation and its evaluative implications. Our findings suggest that the assimilative effect of co-occurrence is potentially ubiquitous, not limited only to co-occurrence due to relations that suggest valence similarity.