Something in the way she moves:the role of motion in facial

attractiveness

Ed Morrison

Parotia

The sociocultural view

• Symons (1997)“…physical characteristics are close to the genes, and are distributed undemocratically. If standards of attractiveness can be shown to vary arbitrarily, attractiveness itself is made to seem trivial”

“Never judge a book by its cover”• People can readily judge attractiveness

– judgments at 150ms exposure correlate with normal judgments (Goldstein & Papageorge 1980)

• What is beautiful is good effect (Dion et al. 1972)– Better careers, personality attributes, marital

outcomes

• Some evidence for a “kernel of truth” in personality attribution

“Beauty is in the eye of the beholder”

• People agree on attractiveness (Feingold 1992)• Meta-analysis r=0.90 (Langlois 1990)

Within cultures Between cultures

Sociocultural view agreement Disagreement

Adaptive view agreement agreement

• Infants distinguish between attractive and unattractive faces (Langlois et al. 1991) even at 1 week old (Slater et al. 1998)

• Infants play more with an attractive doll than an unattractive one (Langlois et al. 1991)

“Beauty is in the eye of the beholder”

“Beauty is only skin deep”• Attractive people:

– fare better in employment (Hosada et al. 2003)– More likely to be acquitted in a trial– Stimulate reward centres in the brain

• Attractiveness important in partner choice– dating (Walster et al. 1966)– Same-sex alliances (Cash & Derlega 1978)– Sexual behaviour (Rhodes et al. 2005)

“Beauty is only skin deep”• Are attractive people actually different

from unattractive people?

• Adaptive view: attractive people have higher mate value– Good genes– Physical condition– Youth, fertility

Facial attraction

Averageness• Francis Galton

Masculinised

Sexual dimorphism

Elephant sealMandrill

Sexual dimorphism

Facial colour

Beyond facial structure• Attractiveness is not just a

fixed property of the face– Emotional expression (e.g.

Otta et al. 1996)– Gaze direction (Kampe et al.

2001)– Other faces (Jones et al. 2007)

• A big missing ingredient– movement

Facial expression

• Is facial attractiveness stable?

• Morrison et al. 2013)

Movement• Static stimuli are limited – real faces are dynamic

• Movement is known to be important for facial perception– sex, identity, emotion

Roberts et al (2009)

Movement

Movement and courtship• Movement is

important in animal courtship (birds, 3-spined stickleback, fruit flies, reptiles)

• Human dance (Brown et al. 2005)

– Symmetrical men produced more attractive dances

Isolating facial movement

• Facial tracking

• Facial tracking

Isolating facial movement

Isolating facial movement

Female attractiveness

- 3

- 1 . 5

0

1 . 5

3

- 3 - 1 . 5 0 1 . 5 3

z ( s e x t y p ic a l i t y )

z(a

ttra

cti

ve

ne

ss

)

F 1

F 2

F 3

F 4

F 5

Coefficient = 1.02, t4=7.08, p<0.001

Intercept error: χ24=15.9, p=0.004

Slope error: χ24=3.7, p>0.500

Male attractiveness

- 3

- 1 . 5

0

1 . 5

3

- 3 - 1 . 5 0 1 . 5 3

z ( s e x t y p ic a l i t y )

z(a

ttra

cti

ve

ne

ss

)

M 1

M 2

M 3

M 4

M 5

Coefficient = –0.31, t4= –1.60, p=0.184 » Morrison et al. (2007)

Male movement

• No cues to attractiveness in male movement?– High agreement on attractiveness

• Menstrual cycle alters preference for facial dimorphism

- Grooming, jewellery, dress- Fantasize about sex

- Go out to bars- Prefer deeper male voices

Female movement• Lap dancers earn more in tips when they

are in the fertile phase of the menstrual cycle (Miller et al. 2007)

• No effect for those on contraceptive pill

• When women are in the fertile phase, they prefer more masculine walkers

• Women with a high sociosexuality prefer masculine walkers

Female movement

http://www.biomotionlab.ca/Demos/BMLwalker.html

Provost, Troje, & Quinsey (2008)

Proceptivity

• Increased preference for

proceptive movement when

fertile

» Morrison et al. (2009)

• Behaviour designed to encourage further interaction in the context of mating

How important is movement?

How important is movement?

• Centroid movement

How important is movement?

• Centroid movement

Correlations

Correlations

Correlations

Results

• Video = a + b1(photo) + b2(point-light) + e

Results• Comparing 3 conditions

etc

Predictions

Attractive movement Unattractive movement

Masculinised Very attractive Not attractive

Feminised Quite attractive Not attractive

Attractive movement Unattractive movement

Masculinised Quite attractive Not attractive

Feminised Very attractive Quite attractive

• Clear preference for feminised female videos

• No preference for dimorphism in male videos

• Analogous with work on static faces

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

video picture

Pre

fere

nce

fo

r m

ascu

lin

isat

ion

MaleAnti

MalePro

FemaleAnti

FemalePro

Morrison et al. 2010

Female body shape• Waist-to-hip ratio (WHR)

• Body mass index (BMI)

Female body shape• E.g. Tovee et al. (1999):

– BMI: 74% variance– WHR: 2.3% variance

Nature and nurture

• Estimate relative importance of dynamic vs static cues

• Estimate relative importance of WHR and BMI in photographs, videos, and point-light walkers

Video Photograph Point-light

Static cues

Dynamic cues

Female body movement

Study 1: stimuli

• Zero-order correlations:

Video Photo Mocap

Video 0.622** 0.720**

Photo 0.357

BMI -0.378 -0.135 -0.555**

WHR -0.624** -0.509** -0.387*

**p<0.01*p<0.05

Female body movement

• Regression models– 1. DV = video attractiveness. Overall

model significant (adj r2 = 0.65, p<0.001)

p

Photo 0.44 0.002

Mocap 0.56 <0.001

Interaction 0.14 0.247

Female body movement

Female body movementDV Video Photo Mocap

Overall model r2 0.38** 0.19* 0.30**

BMI ( -0.17 0.09 -0.44*

WHR ( -0.56** -0.51* -0.26

BMIxWHR ( 0.14 -0.18 0.14

**p<0.01*p<0.05

High heels• Associated with sexuality

• Bad for you– Increases force on knee– Morton’s neuroma in foot nerves– Shortening of Achilles tendon– Bunions– Hard to walk!

• Theories– Push out buttocks and breasts– Slightly increased leg length (Sorokowski &

Pawlowski, 2008)

High heels

High heels• Heels: M = 3.56, SD = 1.21 • Flat shoes: M = 2.36, SD = 1.15, F(1,19) = 76.22, p

<00001, p2 = .80

• Classification error rate = 2 8% in flat shoesand 17% in high heels χ2 (1, N = 120) = 7.06, p = .008. Cramer’s V = .24.

Walker

1 2 3 4 5 6 7 8 9 10 11 12

Mea

n +

SE

Fem

inin

ity R

atin

g

1

2

3

4

5

flats heels

High heels

Flat shoes

M (SD)

High heelsM (SD) Difference

t dfSignificance

Level Cohen's dStride duration (s) 1.13 0.05 1.09 0.05 0.04 1.69 11 0.12 0.80

Cadence (steps/min) 106.4 5.41110.2

2 5.38 -3.82 4.23 11 0.001* -0.71Stride length (m) 1.24 0.05 1.2 0.06 0.04 4.39 11 0.001* 0.73

Knee flexion/extensionHeelstrike (°) -0.39 5.11 -2.98 6.31 2.59 1.62 8* 0.143 0.45Stance max flexion (°) 10.03 5.82 15.96 5.00 -5.93 4.44 8* 0.002* -1.10Toe-off (°) -4.56 3.86 -2.74 5.43 -1.82 0.89 8* 0.401 -0.39Swing max flexion (°) 62.25 3.50 51.48 4.44 10.77 8.46 8* <0.001* 2.71

Hip flexion/extensionHeelstrike (°) 23.75 3.80 29.43 3.12 -5.68 2.75 11 0.019* -1.64Toe-off (°) -9.40 2.12 -9.34 3.76 -0.06 0.07 11 0.945 -0.02Swing max flexion (°) 29.39 3.23 25.87 3.92 3.52 0.04 11 0.971 0.98Pelvic rotation (°) 3.06 1.00 4.16 1.07 -1.1 3.28 11 0.007* -1.06Lateral pelvic tilt (°) 12.34 2.70 14.57 2.69 -2.23 4.90 11 <0.001* -0.83

Shoulder rotation 4.42 2.49 4.38 1.93 0.04 .47 11 0.638 0.02

• Biomechanics

When walking in high-heels women take smaller and more frequent steps, they bend their knees and hips less, and more rotation and tilt occurs at the hip.

Morris, White, Morrison & Fisher, 2012

High heels

• Supernormal stimuli

Static cues Dynamic cues

Shape Colour Texture Current disposition

Condition / current health

Hormone markers

Developmental stability

Here and now

Good genes

The past

Conclusions• Physical attractiveness in terms is best

understood as a product of sexual selection

• However, attractiveness is more than just physical structure

• Movement is an important component of attractiveness

• Other transient aspects of the face (colouration?)

• Physical attractiveness is more than just the face

• Attractiveness is more than just the physical

Acknowledgments

• Prof Ian Penton-Voak

• Dr Andrew Clark

• Dr Isabel Scott

• Dr Robbie Cooper

• Dr Lisa Gralewski

• Dr Neill Campbell

• Dr Pete Etchells

• Dr Paul Morris

• Dr Jenny White

• Hannah Bain

• Louise Pattison

• Hannah Whyte-Smith

• Dave Black

• Wendy Hedger

• Genna Griffiths

• Amy Russell

• Liam Satchell• Dr Robin Kramer