Men with low voices cheat more, and women realize this fact, according to a study led by Jill O'Connor of McMaster University.  The study appeared in Evolutionary Psychology and tackles the subject purely from an evolutionary perspective.

The article first stated that past studies have established the following findings:

-Deep voices in men is associated with higher testosterone levels

-Higher testosterone (or the characteristics of it) is associated with “dominant behavior and social status.”  From a biological point of view, these are the traits females want to pass on to their offspring

-In men, women are attracted to traits (like low voice) that indicate high levels of testosterone.   Some scientists think this is an adaptive evolution tool in women to help them select dominant men.

-However, higher testosterone in men is also associated with “sustained interest in sex beyond their current committed relationship,” “greater number of sex partners,” “a higher number of extra-marital affairs,” and the “mating strategy” of “sexual infidelity.”

-High testosterone in men is also associated with less “relationship investment,” less “parental investment,” and more “short-term mating effort.”

From a reproductive perspective, it certainly makes sense for women to seek dominant males who can pass on their dominant traits and provide for her materially.  However, it also makes sense for women to avoid unfaithful men.

Unfaithfulness incurs costs for both men and women, but it’s arguably more damaging for women, who traditionally needed the help of men to protect and raise their offspring.  The scientists in this study, therefore, hypothesized that women would have the ability to recognize signs of infidelity.

Their tests proved them right.

They discovered that women rate men with lower voices as more likely to cheat than men with higher voices. 

The study concluded that the results are not based on some sort of general or cultural bias; rather, this perception is a biological “adaptive heuristic” that helps women identify potentially unfaithful men.

However, the study didn’t really address how women ultimately view men with deep voices and how they reconcile the attractive trait of dominance with the unattractive trait of infidelity.