• facial asymmetry;
  • assertiveness;
  • dominance;
  • cortisol;
  • testosterone


There is evidence that the cognitive skills that enable an individual to evaluate their own physical characteristics and those of others are an important strategy for recognizing a potential rival in intrasexual competition in humans. It has been shown that these strategies are facilitated by steroid hormones such as testosterone (T) and cortisol (C). This study examines whether men recognize as attractive some facial characteristics of other men that the literature reports as attractive to women when observing the faces of other men, under the hypothesis that the presence of these features indicates a potential rival. The characteristics evaluated were facial fluctuating asymmetry (FA), dominance (D), and assertiveness (A). In addition, we investigated whether the recognition of these facial characteristics depended upon the characteristics of the evaluator, that is, of the man's own FA, D, and A, or on the concentration of T and C in saliva. We found that evaluators with greater FA (asymmetric faces) and lower concentrations of C rated the faces of more symmetrical men as more attractive to women and as the most likely to represent potential rivals. Men with asymmetric faces exhibited higher levels of T than low FA males, although the difference was not significant. Conversely, men with low levels of FA (symmetric) identified the faces of more assertive men as the most attractive to women and the most likely to represent potential rivals. We concluded that men with high FA levels are more prone to recognize a potential rival in others according to female preferences, and this identification enables them to reduce the cost of competition.