Apparently, what attracts women more than a great physique or an attractive face could well be a deep voice, say researchers from Canada and the USA. Men with deep voices are also much more likely to have more children than men who do not have deep voices, the researchers say. You can read about this study in the journal Biology Letters. The scientists said a man's deep voice is a bit like a peacock's tail - it has no survival value, but attracts the female of the species. Testosterone masculinizes the voice at puberty.
Coren Apicella and team interviewed 52 women and 49 men from the Hadza tribe, Tanzania. They were aged from 18-55. There is no birth control in this very large tribe. The researchers chose the Hadza tribe because their lifestyles reflect those of humans thousands of years ago. They are hunter-gatherers. The females gather berries and search for wild plants. The males collect honey and hunt animals. Even though the Hadza are monogamous, extra-marital sex is common. During the interviews, which took place in Swahili, Apicella recorded the voices of the men and women. On studying the recording later they found that the deep voiced men had fathered more children than the non-deep voiced men. The man with the deepest voice had ten surviving children, while the one with the highest pitched voice had three. Apicella suggested that perhaps the males with the lower pitched voices had higher testosterone levels, which attracted them more to females or made them more attractive to them. It is also possible, Apicella added, that men with higher testosterone levels start reproducing earlier in life - they could also be better hunters (a better hunter would bring more food, allowing their wives to have shorter inter-birth intervals).
There was not much Apicella and team could glean from the interviews with the women. It is possible, said the team, that if vocal dimorphism evolved partly due to mate selection, that in the past men and women had more similar voices.