Graded structure and the speed of category verification: On the moderating effects of anticipatory control for social vs. non-social categories

Speeded classification tasks have widely been used as leverage to discern whether exemplars are considered to be typical or atypical members of categories. However, little is known about the possibly different nature of the mechanisms that underlie such reactions for "social" vs. "non-social" categories. We presented participants with typical and atypical exemplars to classify and manipulated the opportunity that participants had to control their responses by varying whether stimulus onset asynchrony (SOA) was short (350ms) or long (2000ms). For non-social categories (e.g., BIRD), participants were faster to classify typical instances than atypical instances, regardless of SOA. In contrast, we predicted and found that manipulating SOA strongly moderated the pattern of response times when motives for control were greater, as was the case when participants were presented with occupations relevant to racial stereotypes (e.g., DOCTORS and JANITORS). The implications of these findings, and their relation to effects observed with gender-based occupational stereotypes, are discussed.