We investigated the relationship between ratings of voice attractiveness and sexually dimorphic differences in shoulder-to-hip ratios (SHR) and waist-to-hip ratios (WHR), as well as different features of sexual behavior. Opposite-sex voice attractiveness ratings were positively correlated with SHR in males and negatively correlated with WHR in females. For both sexes, ratings of opposite-sex voice attractiveness also predicted reported age of first sexual intercourse, number of sexual partners, number of extra-pair copulation (EPC) partners, and number of partners that they had intercourse with that were involved in another relationship (i.e., were themselves chosen as an EPC partner). Coupled with previous findings showing a relationship between voice attractiveness and bilateral symmetry, these results provide additional evidence that the sound of a person's voice may serve as an important multidimensional fitness indicator.
There is growing evidence that the sound of a person's voice may convey important information. Studies have shown that listeners who hear voice samples can infer the speaker's socioeconomic status (Ellis, 1967 and Harms, 1963), personality traits (Allport & Cantril, 1934 and Zuckerman & Driver, 1989), and emotional and mental state attributes related to deception (Ekman et al., 1976 and Streeter et al., 1977). Listeners exposed to voice samples are also capable of estimating the age, height, and weight of speakers with the same degree of accuracy achieved by examining photographs (Krauss et al., 2002, Lass & Colt, 1980 and Lass & Davis, 1976). Independent raters are also capable of matching a speaker's voice with the person's photograph over 75% of the time (Krauss et al., 2002). Hughes, Harrison, and Gallup (2002) found that individuals with symmetrical morphological traits were rated as having more attractive voices, and as deviations from bilateral symmetry increased, ratings of voice attractiveness decreased.
Vocal development is influenced and modified by activational sex hormones during adolescence. Estrogen and progesterone shape the mature female voice, while testosterone modifies the male voice (Abitbol, Abitbol, & Abitbol, 1999) The same hormones that affect voice have also been implicated in the development of sex-specific body configuration features. For instance, waist-to-hip ratios (WHR) in females become more accentuated during puberty, and WHR is an indicator of a female's hormonal profile (increased estrogen) and reproductive status (Singh, 1993). Similarly, during puberty, the male's shoulders broaden, increasing his shoulder-to-hip ratio (SHR). Broad shoulders and narrow hips appear to be shaped by testosterone (Kasperk et al., 1997). Because both voice and WHR/SHR are affected by sex hormones, we examined whether ratings of voice attractiveness were related to variation in SHR and WHR.
WHR and SHR not only influence judgments of attractiveness (Dijkstra & Buunk, 2001 and Singh, 1993), but also, variation in these traits predicts different aspects of sexual behavior in both males and females (Hughes & Gallup, 2003). Women with low WHR (smaller waist compared with the hips) are rated as being more attractive (Beck et al., 1976 and Singh, 1993), report having sex at an earlier age, and report having more sex partners (Hughes & Gallup, 2003 and Mikach & Bailey, 1999). Men with high SHR (larger shoulders and smaller hips) are likewise judged to be more attractive (Dijkstra & Buunk, 2001) and are also more sexually experienced (Hughes & Gallup, 2003). Therefore, we also examined the relationship between ratings of voice attractiveness and different features of sexual behavior.
