title: Something in the way we move: Motion dynamics, not perceived sex, influence head movements in conversation.
abstract: During conversation, women tend to nod their heads more frequently and more vigorously than men. An individual speaking with a woman tends to nod his or her head more than when speaking with a man. Is this due to social expectation or due to coupled motion dynamics between the speakers? We present a novel methodology that allows us to randomly assign apparent identity during free conversation in a video-conference, thereby dissociating apparent sex from motion dynamics. The method uses motion-tracked synthesized avatars that are accepted by naive participants as being live video. We find that 1) motion dynamics affect head movements but that apparent sex does not; 2) judgments of sex are driven almost entirely by appearance; and 3) ratings of masculinity and femininity rely on a combination of both appearance and dynamics. Together, these findings are consistent with the hypothesis of separate perceptual streams for appearance and biological motion. In addition, our results are consistent with a view that head movements in conversation form a low level perception and action system that can operate independently from top-down social expectations.
authors.affiliation: Department of Psychology, University of Virginia, Charlottesville, VA 22903, USA. boker@virginia.edu
authors.forename: Steven M
authors.initials: SM
authors.lastname: Boker
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Cohn
authors.forename: Barry-John
authors.initials: BJ
authors.lastname: Theobald
authors.forename: Iain
authors.initials: I
authors.lastname: Matthews
authors.forename: Michael
authors.initials: M
authors.lastname: Mangini
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Spies
authors.forename: Zara
authors.initials: Z
authors.lastname: Ambadar
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Brick
mesh_terms: D003198:Computer Simulation; D005260:Female; D006801:Humans; D007100:Imitative Behavior; D007398:Interpersonal Relations; D008297:Male; D008960:Models, Psychological; D009039:Motion Perception; D009068:Movement; D009633:Nonverbal Communication; D012016:Reference Values; D012727:Sex Characteristics; D016037:Single-Blind Method; D012938:Social Perception; D014584:User-Computer Interface