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THE EVOLUTIONARY PSYCHOLOGY OF FACIAL BEAUTY. by Gillian Rhodes 14.05.2013 Referee: Laura Broemer. Pro: No gold standard for facial beauty Darwin: large cultural differences in beautification practices. Contra: High agreement across cultures and between men and women on what is attractive
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THE EVOLUTIONARY PSYCHOLOGY OFFACIAL BEAUTY by Gillian Rhodes 14.05.2013 Referee: Laura Broemer
Pro: No gold standard for facial beauty Darwin: large cultural differences in beautification practices Contra: High agreement across cultures and between men and women on what is attractive Early preferences for attractive faces in babies Is beauty a arbitrary cultural convention?
Two questions: • What makes a face beautiful? • pleasant expression • Good grooming • Averageness • Fondness/affection • Youthfulness • Symmetry • Sexual dimorphism • ... • How did these preferences evolve?
Two questions: • What makes a face beautiful? • pleasant expression • Good grooming • Averageness • Fondness/affection • Youthfulness • Symmetry • Sexual dimorphism • ... • How did these preferences evolve?
What makes a face beautiful:Averageness • average trait values for a population • High averageness low distinctiveness
Why Averageness is good: • Signals mate quality • Reflects developmental stability and heterozygosity increased disease resistance • Functionally optimal
Pros Computer-generated averaged composites more attractive What is average, is beautiful:
Pros Computer-generated averaged composites more attractive Cons Composites not really averages What is average, is beautiful:
Pros Computer-generated averaged composites more attractive When controlled for enlarged features still more attractive Cons Composites not really averages What is average, is beautiful:
Pros Computer-generated averaged composites more attractive When controlled for enlarged features still more attractive Cons Composites not really averages Confounded with symmetry What is average, is beautiful:
Pros Computer-generated averaged composites more attractive When controlled for enlarged features still more attractive Average profiles still more attractive Cons Composites not really averages Confounded with symmetry What is average, is beautiful:
Pros Computer-generated averaged composites more attractive When controlled for enlarged features still more attractive Average profiles still more attractive Attractiveness of individual increases by moving their configurations toward an average configuration Cons Composites not really averages Confounded with symmetry What is average, is beautiful:
Why Symmetry is good: • Might signal mate quality • Body asymmetries increase with premature birth, psychosis and mental retardation • Similar relationships for facial asymmetries?
Con Normal faces preferred to perfectly symmetric faces Pro perfectly symmetric faces more attractive than the original faces What is symmetric, is beautiful: Explanation for these conflicting results?
What makes a face beautiful:Sexual Dimorphism Testosterone jaw, cheekbones, brow ridges, center of the face (from brow to bottom of nose), and facial hair Estrogen lip size, smaller chin, higher cheekbones
Femininity • composites of very attractive female faces have more feminine features and are preferred to more average composites • Exaggeration of feminine features increases attractiveness • when people generate beautiful female faces on a computer, they produce faces with more feminine traits than average
Masculinity • composite faces: more feminine male faces are more attractive • Two possible explanations • Normal faces: masculinity correlates with attractiveness • possible curvilinear connection between masculinity and attractiveness • Women prefer more masculine faces during the fertile phase • adaptive preference for „good genes“?
How did these preferences evolve? • Preferences enhance productive success • „Good genes“ model: attractive traits mate quality offspring viability • Fisherian runaway selection (peacock example) • „by products“ model
Attractiveness and Health • Weak associations between (male) attractiveness and mental health, possibly immunocempetence, longevity, physical fitness and sperm quality • Weak associations between health and averageness • Weak to no associations between health and symmetry • Weak associations between health and sexual dimorphism, but only for males! • Associations mostly driven by the faces below the median in attractiveness Explanation?
Summary and future directions • Averageness, symmetry and sexual bimorphism are perceived as attractive • Weak associations between attractiveness and health • Experimental testing of immunocompetence: challenging the immune system • Interaction between facial and body attractiveness? • Individual preferences? Self-similarity?