The more attractive you are, the more likely you are to get jobs and have people be nice to you.

In their new book, psychologists Viren Swami and Adrian Furnham claim, at last, to have unlocked the secrets of attraction. Esther Walker explains what they discovered – and what it can teach us

Are looks everything?

Yes. Sadly, it seems, we really are that superficial. “Study after study shows that people think that what is beautiful is good,” says Adrian Furnham, co-author of The Psychology Of Physical Attraction. The more attractive you are, the more likely you are to get jobs and have people be nice to you. However, you may find solace in the fact that the likes of Marilyn Monroe don’t always get ahead. Studies have found that attractive women are more likely to be discriminated against when they apply for managerial positions.

Does body size matter?

Pick up any fashion magazine today and you could be forgiven for thinking that the ideal female body shape is that of an adolescent boy. Although the most fashionable silhouette in recent years has been an extremely slender one, being skinny can have undesirable consequences.

The Duchess of Windsor may have decreed that a woman can never be too rich nor too thin, but people who are considered too thin can often be at a disadvantage. Studies have shown that people favour those who are of normal weight, and that people caught up in an accident are far more likely to be rescued if they are of a normal weight than their underweight – or overweight – peers.

Of course, slenderness is still seen as a cultural preference. In poorer cultures, being portly can be a sign of wealth, and therefore desirability. In richer cultures, being thin demonstrates that you can afford a good plastic surgeon. People value thinness more “as you move up the social and economic scale”, Furnham says.

That aside, Furnham and Swami found that body size matters little. Being a fairly superficial lot, what we really care about is people’s faces and how attractive they are.

Male facial hair – hot or not?

It depends. Studies conducted in the 1970s and 1980s often came to entirely opposite conclusions about whether bearded men were attractive or not.

Bearded men are usually regarded as looking older and being more masculine, dominant, courageous and confident, but that doesn’t mean that women want to go to bed with them. In fact, some women find them a total turn-off and associate them with being dirty, a big no-no in any culture.

Unlike body shape, beards have no basis in evolutionary history, so whether you like them or not depends on fashion and individual preference. For those in any doubt, here’s a handy guide: Johnny Depp, hot; Alan Sugar, not.

Is there such a thing as the perfect female form?

Marilyn Monroe, the Venus de Milo, Sophia Loren, Scarlett Johansson – at different times, these women have all been considered among the most desirable on earth. What is it about them that makes men go weak at the knees? They are united by the fact that they all boast, or boasted, a low waist/hip ratio.

Used by our hunter-gatherer forefathers to judge the health and fecundity of women, the WHR is one of the best measures of a woman’s attractiveness to men. It explains why men find more curvy figures such as Scarlett Johansson attractive.

To work out WHR, the waist measurement is divided by the hip measurement. Most women’s WHR falls in the range of 0.7 to 1.0. WHRs of 0.7 or 0.8 are deemed most attractive, with attraction decreasing as the WHR increases.

But a woman’s WHR isn’t necessarily lower the thinner she is; it’s about how small her waist is in comparison with the hips. “As women get older, their waists thicken and their fertility goes down in proportion to their age – that explains why a slim waist, a signal of fertility, is attractive.”

But all the evidence points to the fact that a low WHR is most appealing on women with a “normal” BMI (body mass index) range of between 18.5 and 25.

Does a low WHR have universal appeal?

Almost. A study measuring 300 ancient sculptures from India, Greece and some African tribes found that a low WHR was idealised. The authors point out, however, that a Tanzanian tribe, the Hadza, who subsist by foraging for wild foods, are unaffected by the female WHR. Another isolated tribe, the Matsigenka of southern Peru, were also unimpressed by a low WHR, simply preferring the larger lady.

It's all because of what we perceive as healthy. When resources were scarce, being overweight – hence well fed – was good. Today, being overweight is associated with a long list of health problems.

Are bigger boobs better?

Most studies have found little evolutionary evidence to suggest that breast size has anything to do with fertility or health. Studies into the ideal breast size are inconclusive, and the results vary according to personal taste and culture. In terms of importance to attractiveness, studies have repeatedly shown that breast size comes below both body weight and shape. So, you have been told.

Should you wax?

Hairlessness on women is perceived as a good thing, because it is an indicator of youth and fertility. However, total hairlessness on both women and men is not as attractive, as it is a sign of pre-pubescence and therefore the inability to have children.

Male waxing makes little evolutionary sense, as chest hair is a signal of masculinity, but such depilation is common in Western societies; a 2005 study found that 60 percent of men regularly removed body hair. It seems that whether a man waxes is down to personal choice and is largely affected by what has been “learnt” from your culture.

The current obsession with bikini waxes (not to mention the suspiciously tidy knicker-line of David Beckham in his recent adverts for Armani underwear) can be blamed on fashion – there’s no reason we should find it attractive, and some would say they don’t. Sorry, David.

Is it the same for lesbians?

Lesbians have been found to be far less concerned about financial status than straight women. Studies have also found that lesbians have far more flexible ideas about physical attractiveness.

When compared with straight women in a study, lesbians were less concerned with weight, dieting and body image. Another study concluded that both lesbians and bisexual women preferred relatively heavier partners than straight women. A possible reason for this is because one study observed that lesbians were on average heavier than straight women and found most attractive those who resembled themselves.

But saying that all lesbians are fat is controversial, to say the least: one study found that a more likely explanation was that their preferences reflected a rejection of the contemporary fixation on being thin.

Is beauty colour-blind?

Physical attraction is, pleasingly, not racist. Not taking into account personal prejudices and cultural pressures, all races can appeal to all other races – because what’s more important than skin colour to attractiveness is the symmetry of a person’s facial features and body. Evolutionary psychologists argue that only the healthiest people are able to develop symmetry in their faces and bodies, which is why people find Will Smith or Brad Pitt attractive. It’s not just humans: a study of barn swallows found that the females would rather mate with males whose tails were symmetrical, while peahens prefer peacocks with symmetrical tail spots.

The beer-goggles effect – fact or fiction?

You know how it is; that man who, at midnight, looked like the dreamiest hunk in the world turns out the next day to look more like Steve Buscemi's ugly cousin. Most people blame too much alcohol and, while being drunk doesn't help, it's not just hops that make you hop into bed with a monster. A study of singles bars in 1979 found that as the evening wore on, people rated members of the opposite sex as more attractive; the author of the study argued that as time went by and the risk of going home alone increased, the singles downgraded their criteria for attractiveness.

Can a boy be too tall?

Women are always looking for someone tall, dark and handsome, right?

But how much does a man’s height really matter? It was the psychologist Alfred Adler who coined the phrase “Napoleon complex” to describe shorter-than-average men who overcompensated for lack of height by being overaggressive and wanting to rule the world.

It has been proven that taller men have more children than their averagely tall counterparts, and that taller men receive more replies to personal ads. But don’t worry: many studies show that men of average height are more attractive and likeable than very tall men and some research suggests that above-average height can indicate poor health.

How do ugly boys get gorgeous girlfriends?

In personal adverts, men usually emphasise what they are looking for in a woman physically, whereas women typically look for wealth and status. It’s not that looks don’t matter to women; they simply matter less than signals of money and security. It's this that presumably explains why the Formula One supremo Bernie Ecclestone has such pulling power.

There’s also some confusion as to exactly what women look for in a man. Excessive “masculinity” in men’s faces can actually be seen by women as unattractive, as men with very masculine features have been found to be less resistant to disease and parasites. Women often find feminine features attractive on a man. Brad Pitt, continually cited as a paragon of male loveliness, has plump lips and large eyes that wouldn’t look out of place on a woman. This is because women look for a trade-off between good mates and good fathers, and a couple of feminine features on a man suggests to women that they have better fathering skills.

Yet there is at least one physical characteristic that is vital to male attractiveness. Most women prefer men with broad shoulders and a narrower waist.

How interesting is pale?

In most pre-industrial societies, having a tan was an indicator that the woman or man in question worked outdoors, probably as a manual labourer, and had a low social status and income. Historically, pale skin like Nicole Kidman's – an indication that you are rich enough to sit indoors all day – has been revered as beautiful.

In the 20th century, having a tan (especially when the weather in your own country isn't great) became a sign that you were rich enough to fly off to Jamaica in December, and became very desirable. This has been complicated recently by the rise of budget airlines and tanning booths; an all-year tan no longer equals wealth.

The bottom line is that when a skin tone – either light or dark – becomes associated with low economic or social status, it ceases to be attractive.

Why are gay men always at the gym?

While lesbians reject body fascism, gay men embrace it with zeal. Gay men are more likely to be unhappy with their bodies than straight men and are more likely to have an eating disorder. They also idealise slightly underweight bodies. Gay men tend to idealise upper-body strength over other physical aspects. One theory is that overdeveloped musculature is a way for gay men (otherwise thought of as effeminate) to assert their masculinity and to distance themselves from being thought of as girly.

* The Psychology of Physical Attraction by Viren Swami and Adrian Furnham is published by Routledge. – The Independent