Male? Female? Neutral! Using novel polyhedral figures as gender-neutral stimuli in a mental-rotation test

Abstract

This study investigates sex differences in mental-rotation performance using novel, gender-neutral polyhedral stimuli. In contrast to the widely used cube figures, which are often perceived as male-stereotyped, these stimuli were specifically designed to be structurally analogous but less familiar and therefore less gender stereotypical. We hypothesised that such neutral stimuli might reduce sex differences, and that controlling for childhood play behaviour might improve explanatory precision by accounting for experiential differences between male and female participants. A total of 122 participants (83 females and 39 males; M = 25.95 years, SD = 9.26) completed the mental-rotation test and a self-assessment scale. In addition, they assessed the stereotypical nature of the polyhedra and answered a questionnaire assessing childhood gender-role behaviour. Participants confirmed that the novel polyhedral figures did not evoke gender associations, supporting their suitability for bias-reduced mental-rotation testing. Despite contrary expectations, mental-rotation accuracy differed significantly between sexes, whereas reaction times did not. To better understand the observed difference, regression analyses were conducted. These revealed that the effect of sex on accuracy was mediated by childhood play behaviour. While this effect was present across the full sample, correlation analyses suggested it was primarily driven by female participants. Moreover, feminine gender-role behaviour was associated with faster reaction times and worse accuracy, possibly reflecting differences in task engagement and motivational factors. Overall, the results support the interpretation that sex differences in mental-rotation accuracy reflect experiential rather than inherent cognitive factors. This study contributes to mental-rotation research by introducing an alternative stimulus set and by highlighting the need to consider developmental and motivational influences, which might vary with the choice of stimulus material, when interpreting differences in mental-rotation performance.