The Perception of Operational Sex Ratios by Voice

Abstract

Adult sex ratios in a local environment are linked to a wide variety of reproductive behaviors in humans and other animals. When sex ratios are biased, the more numerous sex faces increased competition for mates and is more likely to yield to the sociosexual preferences of the less numerous sex. Despite widespread evidence of the relationship between sex ratios and behavior, we know little about whether or how sex ratios are encoded and perceived. In two experiments men and women showed perceived sex ratios that correlated with actual sex ratios after 1500 ms exposures to groups of simultaneous voices. However, men perceived more female voices than women did, and women perceived more male voices than men did. Women showed better accuracy than men, but only when sex ratios departed markedly from 50%. Increasing the number of simultaneous voices reduced accuracy, but only at extreme sex ratios. Talker age also significantly affected perceived sex ratios, suggesting that perceived operational sex ratios are adaptively linked to the reproductive viability of the local population. The results suggest that listeners automatically encode vocal sex ratio information and that perceived sex ratios are influenced by characteristics of the local population and characteristics of the listener.

Person Perception, Meet People Perception: Exploring the Social Vision of Groups

“…Further, in line with earlier work on the involuntary extraction of race and gender cues in person perception (Ito & Urland, 2003), findings suggest that group racial and gender diversity are also visually (from faces, see X. Yang & Dunham, 2019) and auditorily (from voices, see Neuhoff, 2017) extracted. Together, these findings highlight that perceivers are sensitive not only to the mean representation of social categories within groups but also to the variance of social categories within groups.…”

“…These surprising findings spurred a flurry of subsequent research (see Table 1) that found similar ensemble-coding accuracy for other socially relevant stimuli, including point-light walkers’ heading direction (Sweeny, Haroz, & Whitney, 2013), eye gaze (Sweeny & Whitney, 2014), race (Thornton et al, 2014; X. Yang & Dunham, 2019), humanness (Yamanashi Leib et al, 2016), voices in a crowd (Neuhoff, 2017; Neuhoff & Sikich, 2018), head rotation (Florey et al, 2016), and facial identity (de Fockert & Wolfenstein, 2009; Neumann et al, 2013, 2017). This ability to visually extract summary statistics of groups even extends to metrics such as variance; perceivers accurately report whether a four-person group had more or less variability in terms of emotion, gender, race, and facial dominance compared with another four-person group, again using short exposure times (Haberman, Lee, & Whitney, 2015; Phillips et al, 2018).…”

Sex roles and sex ratios in animals

“…The relationship between ASR and OSR is of particular interest because they both involve sexually mature individuals and because they have been used interchangeably in some studies. ASR and OSR are commonly, but incorrectly, assumed to be almost identical (Kokko & Jennions, 2008; Weir et al ., 2011; Neuhoff, 2017). Instead, the ASR refers to all adult individuals of a population, whether sexually active or not (Veran & Beissinger, 2009; Carmona‐Isunza et al ., 2017), whereas the OSR is determined by the number of males and females that are available and actively seeking mates (Clutton‐Brock & Parker, 1992).…”

Do Local Sex Ratios Approximate Subjective Partner Markets?

“…Instead, it approximated the everyday interactions of individuals and therefore should not be interpreted as indicative of an inability to perceive sex ratios in set groups. Both Alt et al ( 2017 ) and Neuhoff ( 2017 ) demonstrated that participants are able to give accurate sex ratio estimations based on short-term exposure to visual and auditory cues. Against the backdrop of these previous studies, one potential explanation for our findings could be that individual partner market experiences are not a direct representation of macro-structural conditions, i.e., local sex ratios (Blau, 1977 ; Rapp et al, 2015 ; Schwartz, 1990 ).…”