title: Negative frequency-dependent preferences and variation in male facial hair.
abstract: Negative frequency-dependent sexual selection maintains striking polymorphisms in secondary sexual traits in several animal species. Here, we test whether frequency of beardedness modulates perceived attractiveness of men's facial hair, a secondary sexual trait subject to considerable cultural variation. We first showed participants a suite of faces, within which we manipulated the frequency of beard thicknesses and then measured preferences for four standard levels of beardedness. Women and men judged heavy stubble and full beards more attractive when presented in treatments where beards were rare than when they were common, with intermediate preferences when intermediate frequencies of beardedness were presented. Likewise, clean-shaven faces were least attractive when clean-shaven faces were most common and more attractive when rare. This pattern in preferences is consistent with negative frequency-dependent selection.
authors.affiliation: Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, , Sydney, New South Wales 2052, Australia.
authors.forename: Zinnia J
authors.initials: ZJ
authors.lastname: Janif
authors.forename: Robert C
authors.initials: RC
authors.lastname: Brooks
authors.forename: Barnaby J
authors.initials: BJ
authors.lastname: Dixson
mesh_terms: D000328:Adult; D002755:Choice Behavior; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D006197:Hair; D006801:Humans; D008297:Male; D012727:Sex Characteristics
keywords: facial hair; frequency dependence; human evolution; sexual selection
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