Psychology’s research on gender often reinforces gender essentialism, portraying women and men as having innate, biologically-determined psychological traits. This perspective aligns with traditionalist views that justify distinct social roles: men as competitive leaders, women as nurturers. Despite claims of scientific objectivity, empirical evidence for significant psychological sex differences is weak and often exaggerated, with most studies showing overwhelming similarity. The field’s individuocentrism and biological reductionism shift focus from societal factors, such as cultural norms and structural inequality, to innate personal deficits. Consequently, psychology provides explanatory frameworks that validate socially conservative beliefs about gender roles and heteronormativity, despite progressive stances from its professional organisations.