PS4029/30

Perspectives on social attributions

Lecture 7

1. attractive faces deviate from average [recap]

2. sex. dim. and non-human mate choice

3. attitudes to masculinity in human faces

4. Systematic variation in female preferences for sexual dimorphism in male faces

5. Strategic female preferences for masculine males (intro)

Lecture 7: Sexual dimorphism & attractiveness

Perrett et al (1994) showed that very attractive faces are not average

1. Evidence against averageness accounts of attraction [recap]

Average of 60 Average of Most attractive

Hyper-attractive

Exaggerate differences between A + B

A BMost attractive of

3 faces

2. Sex dim and non-human mate choice (Andersson,1994)

IN MOST SPECIES FEMALES CHOOSE MATES WITH EXAGGERATED MASCULINE TRAITS - - WHY??

MASCULINE MALES & GOOD GENES FOR IMMUNOCOMPETENCE

masculine traits caused by testosterone

testosterone is an immunosuppressant

to develop masculine traits you need to have a strong immune system

masculine traits signal heritable immune system strength (but not necessarily current condition)

NON-HUMAN MALES PREFER FEMININE FEMALES

thought to choose feminine females as mates because such

females are fertile

This increases the males chances of increasing their

reproductive success

3. ATTITUDES TO MASCULINITY IN HUMAN F ACES

DO HUMAN MALES PREFER FEMININE FEMALE FACES?

DO HUMAN FEMALES PREFER MASCULINE MALE FACES?

THIS IS A VERY STRONG PREDICTION FROM ANIMAL LITERATURE

femininewarmhonestgood parent

“dad”masculinefeminine

3. ATTIUDES TO MASCULINITY IN HUMAN FACES

Perrett et al. Nature (1998)

masculinecolddishonestbad parent

“cad”

surprisingaversion to masculinityin both male + female faces

4. SYSTEMATIC VARIATION IN FEMALE PREFERENCES FOR

MASCULINE MALES

Although women seem to generally prefer feminine male faces, the strength of this preference seemed highly variable in the

Perrett et al 1998 study

Is this variation in female preferences for sexual dimorphism in male faces random or systematic?

MASCULINITY OF ODOUR

MALE PHEREMONE

(A CHEMICAL SIGNALOF ‘MALE’)

PEOPLE GENERALLYDON’T LIKE MASCULINEFACES

WHAT ABOUT ODOURS?

FEMALE ATTRACTION TO MASCULINITY IN MALE FACES AND ODOURS

r60=0.40, p=0.002

-10

-5

0

5

10

15

20

Pleasantness of male sex pheromone

Pre

ferr

ed

face

ma

scu

linity

(%

)

dislike

64%

neutral

20%

like

17%

Cornwell et al. Proc Roy Soc (2004)

Masculinity preferences and ‘perceptual bias’

Preferences for faces that deviate from average are hard

for perceptual bias accounts to explain

Systematic variation in preferences is also hard for perceptual bias accounts to

explain

5. Strategic female preferences for masculine males (intro)

There are possible benefits (e.g. healthy offspring) to choosing a masculine male for a short-term relationship

(where investment NOT important)

There are possible costs to choosing a masculine male as a long-term partner (e.g. low investment - Mazuur

and Booth 1998, Perrett et al 1998)

Are individual differences in women’s masculinity preferences ‘strategic’?

Key themes

People prefer feminised male and female faces to average or masculinised versions

It is surprising women do not prefer masculine male faces as facial masculinity may signal ‘good genes’ for

immunocompetence

Women’s preferences for masculinity seem to be systematic (some women more tolerant of masculinity than others are), suggesting there may be a strategy at

work

Next week

Strategic female preferences for masculine faces as evident in change in face preferences across the menstrual

cycle

Menstrual cycle, ‘pill’, pregnancy and illness avoidance