The reason why US presidential candidates Donald Trump, Hillary Clinton, and Bernie Sanders seem charismatic is due to their vocal delivery. These candidates varied their pitch from very low to medium and avoided speaking at a higher pitch when speaking with other political figures. On the other hand, they spoke in a wider fundamental frequency range when addressing the public.

“This vocal profile seems to reflect leaders’ use of vocalizations to display dominance while addressing speakers of the same social status,” says Rosario Signorello, a postdoctoral researcher in the Department of Head and Neck Surgery at David Geffen School of Medicine of the University of California, Los Angeles. “They use voice to convey their authoritarian charisma.”

The research team assessed the candidates’ pitch or fundamental frequency (F0) during meetings with other politicians, during political rallies and talk show interviews. They found that all of them spoke in a wider frequency range when speaking in front of voters.

Presidential candidates

Donald Trump and Hillary Clinton. Credits: Wikimedia/Krassotkin, Gage Skidmore, Gage Skidmore

On the other hand, when all three of them spoke with other political figures, they avoided the high frequencies and varied their pitch from very low to medium instead. Apparently, the same voice pattern can also be observed in other mammals that speak with lower frequency voices to signify their size, dominance or power. Moreover, the candidates all used their normal or healthy voice during their appearance in late night shows and other non-political environments. The candidates also use this normal voice pattern when talking to their families.

The researchers are planning to study further the biological basis of charismatic speech and its influence on the social structures in the animal kingdom. This time, they aim to assess nonhuman primates’ voice modulations.

“The goal of this research is to find a link between species, to demonstrate that the similarities in vocalizations between male and female charismatic speakers, in different languages and cultures, are the result of an evolved way of using vocalization by a group’s leaders,” concludes Signorello.