Friends shrink foes: the presence of comrades decreases the envisioned physical formidability of an opponent.

In situations of potential violent conflict, deciding whether to fight, flee, or try to negotiate entails assessing many attributes contributing to the relative formidability of oneself and one's opponent. Summary representations can usefully facilitate such assessments of multiple factors. Because physical size and strength are both phylogenetically ancient and ontogenetically recurrent contributors to the outcome of violent conflicts, these attributes provide plausible conceptual dimensions that may be used by the mind to summarize the relative formidability of opposing parties. Because the presence of allies is a vital factor in determining victory, we hypothesized that men accompanied by male companions would therefore envision a solitary foe as physically smaller and less muscular than would men who were alone. We document the predicted effect in two studies, one using naturally occurring variation in the presence of male companions and one employing experimental manipulation of this factor.