Glenn Wilson PhD, Gresham College, London

1. IN THE BRAIN OF THE BEHOLDER? THE PRINCIPLES OF BEAUTY AND SEX APPEAL Glenn Wilson PhD, Gresham College, London

2. IS THIS AN ATTRACTIVE FACE? WHY?

3. WHO LOVES YOU BABY? Female faces are seen as attractive when they borrow baby signals such as large eyes and small chin. (evolved to evoke parental protection from men). Pop songs call women “baby”; pornographers call them “babes”. Pets use similar infant signals to evoke caretaking in humans. (Balding in older men?) Youth is a prime female commodity because women are more fertile when young.

4. AVERAGING FACES YIELDS ATTRACTIVENESS Pictures from FaceResearch.org, Univ. Aberdeen (Lisa DeBruine & Ben Jones)

5. BEYOND THE AVERAGE While average faces are attractive, optimal attractiveness in a woman has slightly different proportions. These are: bigger eyes, narrower eyebrows, higher cheekbones, fuller redder lips, narrower jaw, and a smaller chin – hyperfemale traits typically enhanced by make-up. Most are attributes of young, sexually mature women aged about 24, although some are characteristic of much younger women (e.g. the ideal lips are typical of a 14 year-old girl). . The face on the left is a composite of female students; that on the right a composite of models. The model composite is rated more attractive. (From alittlelab.com, University of Stirling, 2002).

6. SYMMETRY INCREASES ATTRACTIVENESS Symmetrical faces are judged as more beautiful and having more “mate appeal” both in men and women (even though perfect symmetry is “abnormal”). Symmetry is also desirable in the body – the female partners of symmetrical men have more orgasms, presumably because they are more desirable (Thornhill et al, 1995).

7. Composite photos of women high in oestrogen are judged by men as more attractive than women low in oestrogen. HORMONE LEVELS AND ATTRACTIVENESS (D. Perrett, University of St Andrews, 2005)

8. MACHO MEN IN DECLINE Testosterone makes a man look dominant, but women sometimes prefer feminine features (large eyes, small chin, wide lips, higher arched eyebrows). These suggest traits like empathy & reliability that might make for good parenting. The fossil record suggests that sexual dimorphism in humans has diminished over last 100k yrs. (due to female preference for caring men?) Perrett et al (1998) found that the feminised male face on the left was preferred by women to the average male face on the right.

9. WOMEN’S DUAL SEXUALITY Whether a woman prefers a man who is macho or baby-faced, genetically similar or not, depends upon whether she is in long-term or short-term mating mode. She prefers “real” men, and those less closely related, when mid-cycle, not pregnant, not on the pill and engaged in extra-pair mating (having an affair). When fertile,women seek “good genes”; otherwise they favour “resource provision”. Use of the pill removes the mid-cycle change in mate preference (Alvergne & Lummaa, 2009).

10. GIVING THE BIG EYES Dilated pupilsare usually attractive because they look bigger (= younger) and suggest the other person is interested. This makes a candle-lit dinner more romantic. For men, the larger the better. For women, large pupils are preferred when the female viewer is fertile (mid-cycle & not on the pill ) and the type that likes “bad boys”. The preference for large pupils indicates a short-term mode. Medium pupils are preferred when a long-term mate is sought.

11. BODY OR FACE? If separate ratings are taken for body and face, the face is generally the better predictor of overall attractiveness (Currie & Little, 2009). However, for men the value of the body increases when they are seeking a short fling. Females do not shift focus according to whether they are evaluating men for short or long-term relationships.

12. BRAIN RESPONSES TO BEAUTY Brain reward circuits in the nucleus accumbens and orbitofrontal cortex show greater fMRI activation (signal change relative to baseline) when we view attractive faces (Cloutier et al 2008). Males respond more differentially (esp. in OFC)

13. SEX APPEAL Derives mainly from typical gender differences (e.g. female hourglass figure vs V-shaped torso, height and deep voice of men). These are markers of sex hormones (oestrogen vs. testosterone) and signals of reproductive fitness (fertility and parenting potential).

14. CHILD-BEARING HIPS For women, a key marker of fertility is the waist/hip ratio. Low ratios (.7 to .8) attract men because they signal high oestrogen. By corollary, a compact backside is preferred by women (even for themselves).

15. INNATE RELEASERS Certain stimulus patterns are primed by evolution to trigger sexual arousal. For the human male this includes paired, pink, fleshy hemispheres.

16. Female front Male front Female rear

17. IMPRINTING Innate visual templates are consolidated or modified by early childhood experiences. (inappropriate sexual attachments = fetishism)

18. FEMALE DISPLAYS Nightclubs operate as human leks (sexual display grounds). Males approach females according to the tightness of their clothes, the amount of flesh they expose (esp. in breast area) and the provocativeness of their dancing. Women display more when fertile (mid-cycle). The most successful females display at least 40% of their body and 50% of their breast area (Hendrie et al, 2009). The limit of exposure is where “allure” becomes “brazenness” (signalling promiscuity). Women choose among those men brave (dominant) enough to ask them to dance.

19. THE HUMAN PEACOCK’S TAIL Men shown in a Bentley Continental are rated as more attractive by women than those in a Ford Fiesta (Dunn & Searle, 2009). Men are not influenced by status manipulation. Men’s testosterone increases after driving a Porsche in public and decreases after driving a banger (Saad et al, 2009). Wealth and status are more important markers of “mate value” to women than physical good looks. Body builders are seen as self-absorbed. Intelligence, creativity, sense of humour and generosity (willingness to share resources) are more important to women.

20. THE ANGELINA JOLIE EFFECT Single women complain that “all the good men are taken”. That may be because being already taken makes a man more attractive. Parker & Burkley (2009) found that single women were more attracted to a man if they thought he was already attached. No such “mate poaching” preference was observed for either men (who pursue female targets indiscriminately) or attached women (who prefer single targets).

21. CROSS-CULTURAL AGREEMENT There is much consistency across cultures as to who and what is attractive. The principles of averageness, symmetry, sexual dimorphism and familiarity apply equally in non-Western cultures. Infants (2-3 mths old) share the same standards of beauty as adults, preferring to look at faces that adults find attractive (Langlois, 2000). Standards of beauty are therefore not just cultural artefacts - biological factors (evolved instincts) are also at play. Universal preferences derive from signals of mate quality - indications of youth, health, fitness and fertility.

22. CULTURAL VARIATIONS Some variations do need accounting for. Generally, they relate to more social aspects of mate quality (signals of wealth and status). The value of a suntan has varied throughout history. Pale skin used to be sought because exposure to the sun implied peasant status. More recently, a suntan has been valued because workers were confined to mines and factories, while the rich could afford foreign holidays. Thinness (to the point of anorexia) is prized in Western society, by women more than men. Fatness may be valued where food shortages mean that only the rich can get fat. Youth is prized in Western society; less so in tribal cultures that venerate elders, where pendulous breasts may be preferred over the pert. We tend to value traits that are prototypic within our own group (e.g. hairiness in Scots, smoothness in Chinese). Origins of racial/species separation?

23. FAMILIARITY IS APPEALING An alternative (or supplementary) explanation as to why average faces are attractive is called prototype theory. We are most comfortable with patterns we have come to expect because they are easier to process in the brain. Winkielman et al (2006) demonstrated this exposure principle with non-human stimuli (patterns of dots). This learning effect that could help to explain genetic similarity attraction (the tendency to prefer those closely related to and resembling ourselves) and idolisation (obsession with celebrities, even those that are totally empty). No doubt avatars of beauty are affected by experience and media repetition but this is unlikely to be the whole story.

24. BOOM AND BUST An interesting historic variation is described by Pettijohn & Jungeberg (2004) who found that men’s perception of sex appeal depends upon a nation’s economic health. Playboy “playmates” were more big-eyed, petite and feminine during good times; more mature and motherly in times of economic difficulty. Apparently, we seek fun when things are going well and support/security when times are bad. 1960s 1990s

25. CONCLUSIONS Human evolution is driven by sexual selection as much as by natural selection. What we are today is partly the result of the sexual preferences of our ancestors. Beauty and sex appeal are not inherent in stimulus patterns but rooted in our responses. They are based primarily on signals of health, reproductive and parental fitness. We are seldom conscious of the adaptive value of our choices but simply go on “instinct”.

26. REFERENCES Alvergne, A. & Lummaa, V. (2009) Does the contraceptive pill alter mate choice in humans? Trends in Ecology and Evolution, in press. Currie, T.E. & Little, A.C. (2009) The relative importance of the face and body in judgements of human physical attractiveness. Evolution & Human Behaviour, 30,409-416. Dunn, M.J. & Searle, R. (2009) Effect of manipulated prestige car ownership on both sex attractiveness rating. British Journal of Psychology, in press. Hendrie, C.A., Mannion, H.D. & Godfrey, G.K. (2009) Evidence to suggest that nightclubs function as human sexual display grounds. Behaviour, 146, 1331-1348. Langlois, J.H., et al (2000) Maxims and myths of beauty: A meta-analytic and theoretical review. Psychological Bulletin, 126, 390-423. Parker, J. & Burkley, M. (2009) Who’s chasing whom? The impact of gender and relationship status on mate poaching. Journal of Experimental Social Psychology, 45, 1016-1019. Perrett, D. I., Lee, K.J., Penton-Voak, I. & Little,A.C. (1998) Effects of sexual dimorphism on facial attractiveness. Nature, 394: 884-887. Pettijohn, T.F. & Jungeberg, B.J. (2004) Playboy Playmate curves: Changes in facial and body feature preferences across social and economic conditions. Personality and Social Psychology Bulletin, 30, 1186-1197. Rhodes, G. (2006) The evolutionary psychology of facial beauty. Annual Review of Psychology, 57, 199-226. Saad, G & Vongas, J.G. (2009) The effect of conspicuous consumption on men’s testosterone levels. Organizational Behavior and Human Decision Processes, 110, 80-92. Thornhill, R. Gangestad, S.W. & Comer, R (1995) Human female orgasm and fluctuating asymmetry. Animal Behaviour, 50, 1601-1615. Winkielman, et al (2006) Prototypes are attractive because they are easy on the mind. Psychological Science, 17, 799-806.