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 culturesBetween cultures Sociocultural viewagreementDisagreement Adaptive viewagreement

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 seal Mandrill

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

Isolating facial movement

Female attractiveness Coefficient = 1.02, t 4 =7.08, p<0.001 Intercept error: χ 2 4 =15.9, p=0.004 Slope error: χ 2 4 =3.7, p>0.500

Male attractiveness Coefficient = –0.31, t 4 = –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 ker.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?

Centroid movement

How important is movement? Centroid movement

Correlations

Results Video = a + b 1 (photo) + b 2 (point-light) + e

Results Comparing 3 conditions

etc

Predictions Attractive movementUnattractive movement MasculinisedVery attractiveNot attractive FeminisedQuite attractiveNot attractive Attractive movementUnattractive movement MasculinisedQuite attractiveNot attractive FeminisedVery attractiveQuite attractive

Clear preference for feminised female videos No preference for dimorphism in male videos Analogous with work on static faces 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 VideoPhotographPoint-light Static cues  Dynamic cues 

Female body movement

Study 1: stimuli

Zero-order correlations: VideoPhotoMocap Video 0.622**0.720** Photo BMI ** WHR **-0.509**-0.387* **p<0.01*p<0.05 Female body movement

Regression models – 1. DV = video attractiveness. Overall model significant (adj r 2 = 0.65, p<0.001)  p Photo Mocap 0.56<0.001 Interaction Female body movement

DVVideoPhotoMocap Overall model r **0.19*0.30** BMI (  * WHR (  -0.56**-0.51*-0.26 BMIxWHR (  **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

Heels: M = 3.56, SD = 1.21 Flat shoes: M = 2.36, SD = 1.15, F(1,19) = 76.22, p <00001,  p 2 =.80 Classification error rate = 2 8% in flat shoes and 17% in high heels χ 2 (1, N = 120) = 7.06, p =.008. Cramer’s V =.24.

High heels Flat shoes M(SD) High heels M(SD)Difference tdf Significance LevelCohen's d Stride duration (s) Cadence (steps/min) *-0.71 Stride length (m) *0.73 Knee flexion/extension Heelstrike (°) * Stance max flexion (°) *0.002*-1.10 Toe-off (°) * Swing max flexion (°) *<0.001*2.71 Hip flexion/extension Heelstrike (°) *-1.64 Toe-off (°) Swing max flexion (°) Pelvic rotation (°) *-1.06 Lateral pelvic tilt (°) <0.001*-0.83 Shoulder rotation 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 cuesDynamic cues ShapeColour 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