Facial appearance represents a key source of social information about the personality and health of its wearer. The facial width-to-height ratio (fWHR) has been linked to dominance-related behavior and seems to be part of an evolved system of social dominance. Recent research indicates the perceived age, the age of another person estimated based solely on facial appearance, to be a valid biomarker for health and longevity. In the first study, we investigated the association between fWHR and various personality traits of social dominance. The fWHR was positively linked to physical aggression, psychopathy, and Machiavellianism, but only in men reporting low income. Furthermore, a positive interaction between fWHR and testosterone on narcissism was found. Our second study analyzed whether psychosocial resources for mental health are associated with the perceived age. Optimism, self-esteem, and relationship satisfaction were indirectly associated with a younger facial appearance. Mental health mediated the association between each psychosocial resource and facial appearance. In conclusion, the findings presented in this thesis emphasize the importance of taking into account biopsychosocial factors when examining the link between facial appearance and complex personality traits as well as mental health.