Attractiveness and distinctiveness between speakers' voices in naturalistic speech and their faces are uncorrelated

Abstract

Facial attractiveness has been linked to the averageness (or typicality) of a face and, more tentatively, to a speaker's vocal attractiveness, via the 'honest signal' hypothesis, holding that attractiveness signals good genes. In four experiments, we assessed ratings for attractiveness and two common measures of distinctiveness ('distinctiveness-in-the-crowd', DITC and 'deviation-based distinctiveness', DEV) for faces and voices (simple vowels, or more naturalistic sentences) from 64 young adult speakers (32 female). Consistent and substantial negative correlations between attractiveness and DEV generally supported the averageness account of attractiveness, for both voices and faces. By contrast, and indicating that both measures of distinctiveness reflect different constructs, correlations between attractiveness and DITC were numerically positive for faces (though small and non-significant), and significant for voices in sentence stimuli. Between faces and voices, distinctiveness ratings were uncorrelated. Remarkably, and at variance with the honest signal hypothesis, vocal and facial attractiveness were also uncorrelated in all analyses involving naturalistic, i.e. sentence-based, speech. This result pattern was confirmed using a new set of stimuli and raters (experiment 5). Overall, while our findings strongly support an averageness account of attractiveness for both domains, they provide no evidence for an honest signal account of facial and vocal attractiveness in complex naturalistic speech.

Keywords: attractiveness; averageness; distinctiveness; face; honest signal hypothesis; voice.

Figure 1.

Within-domain correlations between mean ratings of attractiveness and distinctiveness (top: DITC-based distinctiveness; bottom: deviation-based distinctiveness) for faces and voices based on vowels (left: experiments 1 and 2) and based on sentences (right: experiments 3 and 4). Data points represent individual speakers, and are depicted separately for female (black) and male speakers (grey). Correlation coefficients (ρ) are depicted overall, with asterisks indicating significance levels (*p < 0.05; **p < 0.01; ***p < 0.001, uncorrected). Note that the strong and negative correlations between attractiveness and DEV-based distinctiveness (experiments 2 and 4) survived Bonferroni correction for the 48 tests depicted in figures 1 and 2 (electronic supplementary material, tables S1 and S2), with the exception of the correlation for male faces in experiment 2 (corrected alpha level = 0.001). The only other correlation which failed to reach significance after Bonferroni correction was the small positive correlation between voice attractiveness and VITC across all speakers (experiment 3).

Figure 2.

Between-domain correlations between mean ratings of faces and voices based on vowels (left: experiments 1 and 2) and based on sentences (right: experiments 3 and 4). Data are depicted separately for attractiveness and distinctiveness ratings (top: DITC-based distinctiveness; bottom: deviation-based distinctiveness) and for female (black) and male speakers (grey). Correlation coefficients (ρ) are depicted overall, with asterisks indicating significance levels (*p < 0.05; **p < 0.01; ***p < 0.001, uncorrected). Note that facial and vocal attractiveness ratings for the same speakers were generally uncorrelated, with the exception of a small positive correlation when voice attractiveness ratings were based on vowel stimuli (experiment 1). This correlation was no longer significant after Bonferroni correction for the 48 tests depicted in figures 1 and 2 (corrected alpha level = 0.001).