You spend hours in the gym, take regular showers, and even trim your nose hairs on occasion all in the name of attracting women. On most days it even takes you longer to primp that disheveled hair of yours than it takes your girlfriend to get ready, but did you know that all that mangrooming could be a complete waste of time?

In a new study, detailed in a recent issue of the journal Biology Letters, David Feinberg and his group of researchers at McMaster University in Canada set out to see how the attraction to deeper-voiced men affects reproduction rates. Their study showed that what really attracts a woman to a man is the tone of his voice. In fact, of those studied, the deeper-voiced males had fathered 66% more children than the non-deep voiced men.

To look for the relationship between voice pitch and birth rates, the researchers took recordings of the voices of men and women. While studying the recordings later, they found that the deep voiced males had fathered more children than the non-deep voiced men. These studies showed women are more attracted to men with deeper voices because a deeper voice signals that the man is older, wiser, healthier and more masculine than his higher-pitched rivals. The opposite is true for men, who tend to go for women with higher pitched voices, which make them seem more youthful, attractive and feminine.

Testosterone levels increase when a male is going through puberty, which means the attraction to deeper-voiced males can be directly correlated to testosterone levels. This idea goes all the way back to the ice age and primitive thoughts on how men and women chose to procreate. It is a bit like natural selection; the stronger the male, the more attractive he becomes. Since lower pitched voices have higher testosterone levels it is possible that women see these men as strong and protective father figures.

There may not be much you can do to change the voice you were born and bred into, but you might now be able to further manscape your life. The strong survive; though regular grooming can't hurt.