Do Candidates' Voices Convey More Than Their Words?

Republican presidential candidates from left, Donald Trump, Jeb Bush, Mike Huckabee, Ted Cruz and Rand Paul take the stage fo
Republican presidential candidates from left, Donald Trump, Jeb Bush, Mike Huckabee, Ted Cruz and Rand Paul take the stage for the first Republican presidential debate at the Quicken Loans Arena Thursday, Aug. 6, 2015, in Cleveland. Republicans are steeling themselves for a long period of deep uncertainty following a raucous first debate of the 2016 campaign for president, with no signs this past week’s Fox News face-off will winnow their wide-open field of White House hopefuls anytime soon. (AP Photo/Andrew Harnik)

With the presidential election season heating up, all eyes are on the candidates. Recent research indicates that our ears are paying attention, as well. Two new studies suggest that while voters are focused on a candidate's message, they might also be influenced by the tone of the candidate's voice.

My husband, Casey Klofstad, and I have been studying voice qualities and how they influence voters for several years. Casey is a political scientist at the University of Miami, and I am a behavioral ecologist at Florida Atlantic University who studies animal communication, mostly bird song. We teamed up several years ago to study candidate voice perception when we noticed that female political candidates were often criticized in the media for having "shrill" or "irritating" voices.

Our analyses of both real-life elections and data from experiments show that candidates with lower-pitched voices are generally more successful at the polls. A new study by Casey in Political Psychology shows that candidates with lower voices running in the 2012 U.S. House elections were more likely to win their elections. However, these findings become more complex once the sex of the candidate and his or her challenger is accounted for. When facing male opponents, both male and female candidates with lower voices won a larger vote share. But, when facing female opponents, candidates with higher voices were more successful and particularly so in the case of male candidates.

What can these patterns tell us about how voice qualities influence us? In the paper, Casey suggests that because individuals with lower voices tend to have higher levels of testosterone, and because testosterone correlates with physical and social aggressiveness, it could be that male candidates with lower voices are perceived as too aggressive when paired against a female opponent.

That being said, our research shows that voters generally prefer candidates with lower voices. How can we explain this? Casey and I tackled this question in collaboration with Stephen Nowicki (Duke University) in a study recently published in the open-access journal PLOS ONE. In an experiment, we asked study participants to listen to pairs of recorded voices that had been manipulated to vary only in pitch. The "candidates" said, "I urge you to vote for me this November." The study participants were then asked which voice of each pair was stronger, more competent, older, and which voice they would vote for. The results show that the preference for leaders with lower-pitched voices correlates with the perception that speakers with lower voices are stronger, more competent and older. Importantly, however, the influence of age on vote choice is the weakest of the three factors. So while it appears that lower voices are perceived as belonging to older candidates, our perceptions that low voices belong to stronger, more competent people is a better explanation for why we prefer lower-voiced candidates.

Keep in mind that while several studies have now shown that candidates with lower voices may have an advantage at the polls, research has yet to show whether these factors are relevant to a candidate's leadership ability. Clearly there is much work left to do. The "Holy Grail" will be to test whether people with lower voices are actually stronger and more competent leaders.

Taking a broader view, our studies and others like them show that while voters consciously consider their own political preferences and the platforms of the candidates when casting their ballots, voters also make thin, impressionistic judgments based on far more subtle factors -- factors they may not be aware of.