Browsing by Author "Fiala, Vojtěch"

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    Africans and Europeans differ in their facial perception of dominance and sex-typicality: a multidimensional Bayesian approach
    (Scientific Reports, 2022-12) Fiala, Vojtěch; Tureček, Petr; Akoko, Robert Mbe; Pokorný, Šimon; Kleisner, Karel
    AbstractBiosocial impact of facial dominance and sex-typicality is well-evidenced in various human groups. It remains unclear, though, whether perceived sex-typicality and dominance can be consistently predicted from sexually dimorphic facial features across populations. Using a combination of multidimensional Bayesian approach and geometric morphometrics, we explored associations between perceived dominance, perceived sex-typicality, measured sexual shape dimorphism, and skin colour in a European and an African population. Unlike previous studies, we investigated the effect of facial variation due to shape separately from variation due to visual cues not related to shape in natural nonmanipulated stimuli. In men, perceived masculinity was associated with perceived dominance in both populations. In European women higher perceived femininity was, surprisingly, likewise positively associated with perceived dominance. Both shape and non-shape components participate in the constitution of facial sex-typicality and dominance. Skin colour predicted perceived sex-typicality in Africans but not in Europeans. Members of each population probably use different cues to assess sex-typicality and dominance. Using our methods, we found no universal sexually dimorphic scale predicting human perception of sex-typicality and dominance. Unidimensional understanding of sex-typicality thus seems problematic and should be applied with cautions when studying perceived sex-typicality and its correlates.
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    Facial attractiveness and preference of sexual dimorphism: A comparison across five populations
    (Evolutionary Human Sciences, 2021) Fiala, Vojtěch; Třebický, Vít; Pazhoohi, Farid; Leongómez, Juan David; Tureček, Petr; Saribay, S Adil; Akoko, Robert Mbe; Kleisner, Karel
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    Predicting strength from aggressive vocalizations versus speech in African bushland and urban communities
    (Philosophical Transactions of the Royal Society B: Biological Sciences, 2021-12-20) Kleisner, Karel; Leongómez, Juan David; Pisanski, Katarzyna; Fiala, Vojtěch; Cornec, Clément; Groyecka-Bernard, Agata; Butovskaya, Marina; Reby, David; Sorokowski, Piotr; Akoko, Robert Mbe
    The human voice carries information about a vocalizer's physical strength that listeners can perceive and that may influence mate choice and intrasexual competition. Yet, reliable acoustic correlates of strength in human speech remain unclear. Compared to speech, aggressive nonverbal vocalizations (roars) may function to maximize perceived strength, suggesting that their acoustic structure has been selected to communicate formidability, similar to the vocal threat displays of other animals. Here, we test this prediction in two non-WEIRD African samples: an urban community of Cameroonians and rural nomadic Hadza hunter–gatherers in the Tanzanian bushlands. Participants produced standardized speech and volitional roars and provided handgrip strength measures. Using acoustic analysis and information-theoretic multi-model inference and averaging techniques, we show that strength can be measured from both speech and roars, and as predicted, strength is more reliably gauged from roars than vowels, words or greetings. The acoustic structure of roars explains 40–70% of the variance in actual strength within adults of either sex. However, strength is predicted by multiple acoustic parameters whose combinations vary by sex, sample and vocal type. Thus, while roars may maximally signal strength, more research is needed to uncover consistent and likely interacting acoustic correlates of strength in the human voice. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part I)’.