Physical attractiveness (hence attractiveness) plays an important role in human mate choice (e.g., Buss, 1989 and Rhodes et al., 2005), a role that has been explained within the theoretical framework of sexual selection (e.g., Buss & Schmitt, 1993, Gangestad & Simpson, 2000, Johnston, 2006 and Symons, 1979). From this viewpoint, the perception of attractiveness is an evolved adaptation, which promotes preferential mating with individuals of high mate value (i.e., individuals who increase their partner's reproductive success above the level expected in case of random mating).
Several aspects of ancestral life make performance-related physical fitness (PF) a likely component of ancestral men's mate value. Performance-related PF (hence PF) depends on motor skills, cardiorespiratory power, muscular strength and endurance, body composition, and other factors (Bouchard & Shepard, 1992) and largely reflects the ability to perform work (i.e., to exert power along distance). Throughout the longest time of human history, subsistence strongly depended on physical activity. Life included long walks and hunting. Physically fit men, as compared to their less fit peers, (a) could probably better care for themselves and their family without risking health-threatening overexertion (Mackinnon, 2000); (b) they were better prepared for the challenges of male-male violence ubiquitous in ancestral life (Keeley, 1996); and (c) they could use aggression more successfully to co-opt the resources of others, to elevate their own status and to protect their mates and their mates' children against violence (Buss, 2004 and Smuts, 1992). Finally, (d) physically fit fathers probably bestowed this advantage to their offspring because PF has a considerable heritable component (Maes et al., 1996 and Malina & Bouchard, 1989).
If PF was important to ancestral men's mate value, and if attractiveness signals mate value, then PF and attractiveness should be positively related in men. To investigate this hypothesis is our main objective. Thus far, only indirect evidence supports this hypothesis. First, Hönekopp, Bartholomé, and Jansen (2004) reported a positive relationship between facial attractiveness and PF in young women. Second, several experimental studies using line drawings have found female preferences for male figures with a medium body mass index and a pronounced upper body v-shape, a likely indication of a lean, muscular physique and, thus, PF (Dixson et al., 2003, Furnham & Baguma, 1994, Horvath, 1981 and Lavrakas, 1975; but see Gitter, Lomranz, & Saxe, 1982 for conflicting results). Moreover, two correlational studies using more realistic stimuli supported these experimental results: Fan, Dai, Liu, and Wu (2005), using 3D wire frame film clips, and Maisey, Vale, Cornelissen, and Tovée (1999), using front view photographs, found male bodies with low body mass index, broad chests and small waists to be attractive for women. Third, women positively respond to faces rated high for masculinity (Cunningham et al., 1990, Koehler et al., 2004 and Rhodes et al., 2003). Facial masculinity may indicate high testosterone levels (e.g., Johnston, 2006 and Penton-Voak & Chen, 2004), and testosterone promotes muscle growth (Bhasin, Woodhouse, & Storer, 2001). Therefore, women's preference for masculine faces may indicate a preference for muscular and, thus, physically fit men.
A potential relationship between attractiveness and PF in men has not been investigated yet. Our objective is to close this gap. We also analyze testosterone, rated masculinity, upper body v-shape, body mass index, and height as potential mediators for the hypothesized relationship between men's attractiveness and their PF. Given that attractiveness has the function to promote mating with individuals of high mate value (see above), we also expect that PF and mating success are positively correlated in men and that attractiveness mediates this relationship.
