Elections aren’t won or lost on policy points alone. There’s also the candidate’s personality to consider, their fundraising abilities, and … their tone of voice. 

Casey Klofstad, a political scientist at the University of Miami, conducted two different studies on how voice pitch affects voting, finding that lower-voiced candidates resonate better with voters. The studies, in the journals PLOS ONE and Political Psychology, include both experimental setups where participants listened to voices manipulated to be higher and lower, and analysis of real election results from the 2012 U.S. House elections. 

In several experiments with hundreds of study subjects, participants voted in a mock election between candidates of different ages and genders. Participants listened to two random candidates, both male or both female, saying “I urge you to vote for me this November,” and choose which one of them they’d be more likely to trust and vote for. In another experiment, videos of 796 candidates who ran for the House of Representatives in 2012 were analyzed to determine the relative pitch of their voices compared to their opponents.

Participants were more eager to vote for candidates with lower voices, and candidates in the actual House elections were generally more likely to win if they had a lower pitch. However, when a male Congressional candidate faced off against a woman, the man was more likely to win if he had a higher voice. In one of the theoretical experiments, participants linked lower voices to being stronger and more competent leaders, as well as older, though that didn’t seem to matter as much for electability. The deep-voice effect was strongest when participants were judging candidates of their own gender—men voting for men, women voting for women. 

The studies can prove only a correlation between deep-voiced candidates and electoral victories, and they could not determine whether those lower-voiced candidates also happened to be more effective or charismatic leaders. However, it does bring up the possibility of a subtle bias against high-pitched voices in politics. This may be particularly problematic for women, whose voices are twice as high as men’s, on average, and already face barriers toward winning office.