Physical strength and gender identification from dance movements Carla Hufschmidt a , Bettina Weege a , Susanne Röder b , Katarzyna Pisanski c , Nick Neave d , Bernhard Fink a,⇑ a Institute of Psychology and Courant Research Center Evolution of Social Behavior, University of Göttingen, Kellnerweg 6, D-37077 Göttingen, Germany b Department of General Psychology and Methodology, University of Bamberg, Markusplatz 3, D-96047 Bamberg, Germany c Department of Communication Studies, Center for Behavior, Evolution and Culture, University of California, Los Angeles, CA 90095 United States d Department of Psychology, Northumbria University, Newcastle upon Tyne NE1 8ST, United Kingdom article info Article history: Received 5 November 2014 Received in revised form 20 November 2014 Accepted 21 November 2014 Keywords: Dance Gender identification Physical strength Handgrip Men Women abstract Here we show that gender identification of male (but not female) heterosexual, right-handed dancers correlates with physical strength (measured via handgrip strength) after controlling for the effect of body-mass-index on strength. Using optical motion capture technology, we collected the dance move- ments of men and women for subsequent animations of uniform shape- and texture-standardized virtual characters (avatars). Short video clips (15 s) of these movements were presented to male and female adults and children, who were asked to identify the gender of the avatar. Gender identification perfor- mance was significantly higher than chance for both adults and children. Among adults (but not among children) the avatars of male dancers who were physically stronger were perceived as males significantly more often than were the avatars of male dancers who were physically weaker. There was no relationship between strength and gender identification for female dancers. We conclude that physical strength affects gender identification from human dance movements at least for male dancers, and that pre- pubertal children might not be sensitive to strength cues in dance movements. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Gender constitutes a key facet of an individual’s personal and social identity as it influences virtually all aspects of social commu- nication and social life (Deaux & Major, 1987; Money & Ehrhardt, 1972; West & Zimmerman, 1987). The expression of gender, and our ability to differentiate the gender of others, is often influenced by various physical traits and characteristics. Research suggests that observers can use sexually dimorphic physical features such as body height, weight, muscularity, body hair, facial morphology, and voice pitch, to accurately differentiate adult men and women (Neave, 2008; Puts, 2010). Gender identification has been demon- strated in infants aged 10 months old (Levy & Haaf, 1994) showing that the cognitive abilities required for categorizing social informa- tion, such as gender, are present early in life. Studies using dynamic point-light walkers have demonstrated that adult observers can also accurately judge gender from gait (i.e., an individual’s walk) in the absence of all other physical or behavioural cues to gender (Barclay, Cutting, & Kozlowski, 1978; Kozlowski & Cutting, 1977, 1978; Mather & Murdoch, 1994; Sumi, 2000; Troje, 2002). The ability to identify the gender of a person based simply on motion cues implies characteristic differ- ences in the way that men and women move their bodies (Pollick, Kay, Heim, & Stringer, 2005; Pollick, Paterson, Bruderlin, & Sanford, 2001). Cutting, Proffitt, and Kozlowski (1978), for exam- ple, reported that men swing their shoulders from side to side more than do women while walking, whereas women swing their hips from side to side more than do men. Indeed, when asked to make judgements of the gender of an animated walker, observers focus primarily on the shoulders and hips (Saunders, Williamson, & Troje, 2010). Other studies suggest that the motion of the legs provides important sex-relevant information (Todd, 1983; Yamasaki, Saki, & Torii, 1991). Thus, gait appears to communicate cues to gender that adult observers are sensitive to. It is not clear what factors contribute to differences in the way that men and women move, and whether observers utilize these same factors to assess gender. Recent work suggests that sexually dimorphic traits affect body movement in a way that may provide observers with socially relevant, sex-specific information. Sexually dimorphic characteristics develop under the influence of sex ste- roid hormones, most notably testosterone, and provide the basis for many subsequent observations of sex-specific behaviours in adulthood (Neave, 2008). In perceptual studies of body movement, physical strength appears to be a key sexually dimorphic charac- teristic affecting social perception. Men are on average twice as strong as are women (Miller, MacDougall, Tarnopolsky, & Sale, http://dx.doi.org/10.1016/j.paid.2014.11.045 0191-8869/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +49 551 39 9344; fax: +49 551 39 7299. E-mail address: bernhard.fink@ieee.org (B. Fink). Personality and Individual Differences 76 (2015) 13–17 Contents lists available at ScienceDirect Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid