Individuals use facial width-to-height ratio (fWHR) to infer dominance and fighting ability of others. We hypothesized that broad assessments of target formidability from fWHR would form a basis for determining men’s coalitional value, with high-fWHR men being especially valuable in roles requiring physical strength. Across five studies (N=1,445), we identified the social affordance of male facial structures connoting formidability and how judgments influence coalitional decisions. In addition to replicating previous findings indicating high-fWHR men are more desirable for tasks requiring physical strength, we found that such men are aversive for tasks requiring creativity (Studies 1 and 2). High-fWHR men were additionally perceived as more effective in combat roles in the military (Study 3). Finally, in two pre-registered studies, we found that activation of competitive motivations heightens individuals’ interest in formidable allies during intergroup interactions (Study 4), but not interest in approaching them (Study 5). We interpret findings using evolutionary and social affordance theories and discuss hypothesized ancestral origins of selecting formidable allies.