Candidates' voice in political debates and the outcome of presidential elections

According to rational choice theory, a voting decision is based on information about candidates and the political positions they hold. However, a large body of research showed that voters do not know enough about politics and that they rely on cues that signal quality of potential candidates. For example, they are more prone to vote for a candidate who shows signals of dominance, social influence, and masculinity. These characteristics were important in our evolutionary history and are related to testosterone levels. Vocal characteristics are also related to testosterone levels ; those individuals with higher testosterone levels have a deeper voice. Experimental laboratory studies showed that voice pitch has an impact on voting decisions. In order to verify and expand these results we checked whether vocal characteristics of actual presidential candidates are related to election outcomes. Using recordings of presidential debates we show that those candidates who have a deeper voice, greater pitch variability, higher minimal and lower maximal frequency have a higher probability of winning the election. These results offer an external validity of previous laboratory studies and are interpreted within the framework of evolutionary political psychology.