Abstract It is common that marketers design and position pretty products more to female consumers than to male consumers, suggesting they generally believe that females have a stronger preference than males for product form over function and apply this belief to their marketing practices. However, this research demonstrates that this belief is often inconsistent with actual preferences. Across seven studies and four follow-up studies, involving both hypothetical and field settings, we demonstrate that both marketers and consumers hold such a belief about gender difference and overpredict females’ preference for form-superior (vs. function-superior) products relative to males. Specifically, people tend to choose form-superior (vs. function-superior) products for female (vs. male) others, but female consumers do not choose form-superior (vs. function-superior) products for themselves more than do male consumers. We further provide convergent evidence for the underlying mechanism and boundary conditions by showing that a) people’s choices for others and themselves are more in line with the lay belief about gender difference when they hold a stronger belief, and b) people’s choices for distant (vs. close) others are more in line with this lay belief. We further assess the effectiveness of several debiasing interventions and show that this lay belief is quite robust.