Facial width to height ratio and perceived aggression: The disjunction effect of horizontal and vertical components

Facial width-to-height ratio (fWHR) is associated with aggressive behavior and perceived aggression. This study examined the independent effects of the horizontal and vertical components of fWHR on general aggression perception and specific aggression in romantic relationship (intimate partner violence, IPV) perception. By increasing width, the horizontal component of fWHR significantly increases the IPV perception. By reducing height, the vertical component of fWHR significantly decreases the IPV perception (Study 1). Upper and lower facial heights were reduced simultaneously in the vertical manipulation, indicating mixed effects. In Study 2, we separated the upper and lower face effects. Reducing upper face height could facilitate aggression perception. However, reducing the lower face could suppress aggression perception. The results indicated the disjunction effect of horizontal and vertical components on aggression perception. Our findings highlighted the effect of the lower face on aggression perception, which was ignored in previous studies.