THE EVOLUTIONARY PSYCHOLOGY OFFACIAL BEAUTY

by Gillian Rhodes14.05.2013Referee: Laura Broemer

Pro:• No gold standard for

facial beauty• Darwin: large cultural

differences in beautification practices

Is beauty a arbitrary cultural convention?

Contra:• High agreement

across cultures and between men and women on what is attractive

• Early preferences for attractive faces in babies

Two questions:1. What makes a face beautiful?- pleasant expression- Good grooming- Averageness- Fondness/affection- Youthfulness- Symmetry- Sexual dimorphism- ...

2. How did these preferences evolve?

Two questions:1. What makes a face beautiful?- pleasant expression- Good grooming- Averageness- Fondness/affection- Youthfulness- Symmetry- Sexual dimorphism- ...

2. 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

What is average, is beautiful: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 makes a face beautiful:Symmetry

Why Symmetry is good:

• Might signal mate quality• Body asymmetries increase with

premature birth, psychosis and mental retardation

• Similar relationships for facial asymmetries?

What is symmetric, is beautiful:

Con• Normal faces

preferred to perfectly symmetric faces

Pro• perfectly symmetric

faces more attractive than the original faces

Explanation for these conflicting results?

What makes a face beautiful:Sexual Dimorphism

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

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?

Thank you for your attention!