A deep male voice is often considered an advantage both in love and in competition. But new data published in the journal Royal Society Open Science show that when a person sees a man in full rather than only hearing him, a low timbre does not make him more attractive to women. It does, however, make him seem stronger and more dominant.
Scientists James Rutter and Linda Boothroyd of Durham University conducted two experiments. In the first, they filmed 17 men aged 19 to 32 - white Britons of different builds. They stood at full height in identical neutral clothing and counted from one to five. Then, using an acoustic program, each man's voice was altered in pitch and timbre - resonance, that is, the depth and richness of the sound. The result was 12 versions of video for each man.
Then 1,466 American adults aged 18 to 36 watched randomly selected clips and rated one quality. Heterosexual women gave scores for attractiveness, men for physical strength and fighting ability, and a mixed group for social dominance, that is, how respected and influential the person seems among peers. Separate groups rated the same videos without sound.
The results showed that lowering the voice did not increase attractiveness compared with the average level. Women rated high voices lower, and very low voices seemed to them less attractive than merely low ones. The difference between a low and an average voice was statistically insignificant. Strength, fighting ability and social dominance, however, rose as the voice was lowered - here a clear pattern was seen.
At the same time, appearance still outweighed voice. Silent video explained roughly 12 to 38 percent of the variance in ratings, while voice changes explained only 1 to 5 percent. For example, lowering pitch by 20 hertz raised estimated success in a fight by just 1 percentage point - say, from 50 to 51 percent.
In the second experiment, 542 men watched the same clips, but first they were shown a reference clip with the person's real height and weight. Participants guessed the weight or height of the men in the video. It turned out that from a lowered voice the men seemed slightly heavier - on average by 0.34 kilograms when pitch was lowered by 20 hertz. It did not affect the estimate of height. The authors suggest that it is precisely this illusion of extra weight that may explain why a low voice strengthens the sense of physical power. Admittedly, weight and dominance were rated by different groups of people, so the study cannot directly link one to the other.
The work has limitations. All participants lived in Western countries, and the models were Britons of different builds - from slim to heavy. The recordings lasted only a few seconds, and the men spoke in an even tone. In addition, the effects turned out to be small, and the authors emphasize that their results do not prove that voice directly affects attractiveness or dominance in real life. This concerns statistical associations that by themselves do not confirm causality.