When motivation backfires: Optimal levels of motivation as a function of cognitive capacity in information relevance perception and social judgment

Motivation and cognitive capacity are central variables in major models of social judgment and persuasion. However, the exact
nature of their interplay in judgment processes has remained ambiguous. The present paper reports on two experimental studies
tackling this issue. In Study 1 we demonstrated a cross-over pattern of means for the interaction effect of motivation and
cognitive capacity on judgment, with high motivation being beneficial under high cognitive capacity but detrimental under
low cognitive capacity. This effect was explained by the participants’ subjective perception of information relevance. In
Study 2, the role of information relevance was further investigated, showing that for highly motivated participants, judgment
was differently affected by information with low versus high relevance when cognitive capacity was high but not when it was
low. In the discussion, we elaborate on these effects, advocating a more dynamic perspective on (social) judgment, acknowledging
the conditional (opposite) effects of motivation, in function of cognitive capacity.