Voice Frequency Manipulations Affect Women’s Perceptions of Trustworthiness and Cooperativeness

Abstract

The focus of this thesis is to investigate the role of voice pitch (the perception of fundamental frequency and/or corresponding harmonics) and apparent vocal tract length (VTL-the perception of the vocal tract resonances i.e. formant frequencies) in perceptions of trustworthiness and other related social attributions. Past research has found that women trust men with relatively higher pitched voices as long-term romantic partners. People with relatively higher pitched voices are also judged as more cooperative than people with relatively lower pitched voices. However, women choose men with relatively lower pitched voices when asked to select which leaders are more trustworthy and make better economic decisions. In study 1, I used “The Trust Game” to determine whether women trust men with higher or lower pitched voices to evenly divide a sum of money. Women trusted men with relatively higher pitched voices more often. Thus, even though men with lower pitched voices are more often elected to office, and are CEOs of larger companies that make more money, women trust men with relatively low pitched voices less than men with relatively high pitched voices to equitably distribute money. Surprisingly, no studies have examined the relationship between VTL and trust, but one recent study examined the relationship between VTL and perceptions of cooperation. In study 2, I was the first to test the role of voice pitch and VTL on perceptions of trust and cooperation. In general, people with higher frequency voices (high pitch and a shorter VTL) were relatively more cooperative and trustworthy than people with lower frequency voices (low pitch and a longer VTL). Despite correlations between the effects of voice frequency manipulations on ratings of trustworthiness and cooperativeness, the amount to which people thought pitch and VTL affected cooperativeness and trustworthiness was different enough to determine that these two constructs overlap, but are not synonymous. Together, these studies show that despite the fact that masculine men tend to win political elections and run large and successful companies, they are viewed as uncooperative and untrustworthy. Future research should investigate if those who win political elections and run successful companies do so because they keep more than their fair share of money.