While a candidate's voice pitch sways voters, it doesn't result in better leaders

But is voice pitch a reliable signal of leadership quality? And is the bias in favor of selecting leaders with lower voices good or bad for democracy?

Researchers from Florida Atlantic University and the University of Miami are the first to address these questions in a study published in the journal Evolution and Human Behavior.

To determine if there is a correlation between voice pitch and leadership ability, Rindy Anderson, Ph.D., an assistant professor in the Department of Biological Sciences in FAU's Charles E. Schmidt College of Science, and Casey Klofstad, Ph.D., an associate professor in the Department of Political Science at the University of Miami, conducted an observational study and an experimental study.

The observational study correlated a measure of the voice pitch of members of the United States Congress with a measure of their leadership ability to test whether members with lower-pitched voices are more effective leaders. The researchers predicted that if voice pitch contains information about leadership ability, then individuals with lower-pitched voices would show evidence of being more effective elected officials. The data they used to test this prediction was based on a power ranking of the members of the 109th U.S. Congress created by Knowlegis.

The experimental study required participants to respond to persuasive political policy statements such as "You should support stronger gun control laws," "You should support deportation of illegal immigrants," or "You should support same-sex marriage," delivered with different pitched voices. The researchers wanted to test the prediction that if individuals with lower-pitched voices are better leaders, then they also should be more persuasive when making policy appeals.

Results from the study reveal that while voters prefer to vote for candidates with lower sounding voices, elected officials with lower voices are not necessarily better leaders. Members of Congress with lower voices are not more effective legislators, and speakers with lower voices are not more persuasive when making statements about governmental policies.

Prior research by Anderson and Klofstad showed that voters in the U.S. generally prefer to vote for candidates with lower voices. Their results were based on both laboratory experiments and from studies of real elections, and are consistent regardless of whether the voter and/or candidate is male or female.

These previous results led them to question whether voters are making good choices based on the sound of candidates' voices. Through the observational and experimental studies, Anderson and Klofstad found no relationship between a candidate's voice pitch (highness or lowness of the voice) and his or her leadership ability.

Overall, these findings address the important question of whether voters' bias in favor of selecting leaders with lower voices is beneficial or harmful to democracy. The results found by Anderson and Klofstad suggest that this perceptual bias is neither: voters influenced by the tone of a candidate's voice are not selecting stronger or more effective leaders, but neither are they selecting "worse" leaders.

Study participants included a total of 344 men (ages 39 to 75 years) and 433 women (ages 19 to 76 years) from the 2016 Cooperative Congressional Election Study post-election survey, conducted online by YouGov between Nov. 9 and Dec. 14, 2016. There were 287 Democrats, 198 Republicans and 219 Independents.