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Human behaviour is based on experiences, environments, evolution and, above all, sex.According to psychologists Alan Miller and Satoshi Kanazawa, these instincts are not politically correct.
The pair say men are classically conditioned to love busty blondes, beautiful people are more likely to have daughters, and they explain why most suicide bombers are Muslim.
Psychology Today put together a fascinating read on 10 of these findings, adapted from Miller and Kanazawa’s 2007 book, Why Beautiful People Have More Daughters. We scoured the essay and extracted the best facts for you here.
Long blonde hair, blue eyes, a slender figure, and big breasts really are the winning combination, psychologists say. All are symbols of youth and thus, fertility.
According to Miller and Kanazawa, shiny, long hair indicates years of good health (hair loses luster over time).
Blonde hair is attractive because it changes more visibly with age. Young blondes have lighter shades and, as they age, the colour darkens.
Slender women with hips are also attractive because 'they are healthier and more fertile than other women,' say Miller and Kanazawa. 'They have an easier time conceiving a child and do so at earlier ages because they have larger amounts of essential reproductive hormones.'
Large breasts also symbolise youth. According to Harvard anthropologist Frank Marlowe, 'Heavier, breasts sag more conspicuously with age than do smaller breasts. Thus they make it easier for men to judge a woman's age (and her reproductive value) by sight.'
The blue-eyed preference has to do with pupil dilation. 'It is an honest indicator of interest and attraction. And the size of the pupil is easiest to determine in blue eyes,' Miller and Kanazawa say.
Even though hair dying and breast augmentation are false symbols of youth, men are still attracted to these unnatural enhancements. It's in their genes, scientists say. Men can't help it, even when they know it's fake.
Throughout history, polygyny (men marrying multiple women) is prominent, and it has to do with survival of the fittest.
If one man has multiple wives, his competitors (other men) will have smaller reproductive pools.
In societies with immense inequality (people are extremely rich and extremely poor, etc), multiple women became attached to the same man and shared his wealth; This 'sharing of resources' was a female survival mechanism.
Now that men are more equal (industrialisation helps keep a balance), monogamy has become commonplace. Still, women are naturally drawn to taller men; it's a protection-driven instinct.
Men usually think they'd be better off in a polygamous environment.
What man wouldn't like to sleep with multiple women and not get in trouble?
But they're wrong. Men benefit from monogamy while women benefit from polygyny.
Again, it boils down to competition and limited resources. When rich men are polygamous, multiple women benefit. When they're monogamous, more women get stuck with poor men, say Miller and Kanazawa.
The only exceptions are women who make their own money or who are extremely hot. Then a woman can monopolize one man's (or her own) wealth; she doesn't have to share.
In a monogamous culture, most men can find wives. In a polygamous culture, only the most desirable men do. The rest end up alone.
When suicide bombers are religiously driven, they're almost always Muslim, says Oxford University sociologist Diego Gambetta.
But not for the reasons you'd think.
'From the evolutionary psychological perspective, Muslim suicide bombing may have nothing to do with Islam or the Koran (except for two lines in it),' Miller and Kanazawa write. 'It may have a lot to do with sex, or, in this case, the absence of sex.'
They explain that Islam, unlike most other religions, 'tolerates polygyny.' And as you just learned, in polygamous cultures, only the most desire able men have wives (and sex).
'Across all societies, polygyny makes men violent, increasing crimes such as murder and rape, even after controlling for such obvious factors as economic development, economic inequality, population density, the level of democracy, and political factors in the region,' they say.
'The other key ingredient is the promise of 72 virgins waiting in heaven for any martyr in Islam. And nearly all suicide bombers are single.'
Researches have found that families with at least one son are much less likely to get divorced. This has to do with the father's sense of self-worth.
'A man's mate value is largely determined by his wealth, status, and power--whereas a woman's is largely determined by her youth and physical attractiveness,' say Miller and Kanazawa. Since appearance is out of a father's control but monetary success is not, fathers subconsciously feel their presence is more valuable for sons.
'There is relatively little that a father (or mother) can do to keep a daughter youthful or make her more physically attractive,' they write. So if a father feels helpless, he may be more inclined to wander and get divorced.
Whether you'll have a boy or a girl is entirely up to chance, right?
Not exactly, Miller and Kanazawa say.
Normally, the boy to girl birth ratio is 100 to 105 respectively. But nature can change that.
'Natural selection designs parents to have biased sex ratios at birth depending upon their economic circumstances--more boys if they are wealthy, more girls if they are poor. (The biological mechanism by which this occurs is not yet understood.)'
This idea that parents are more likely to pass on their best traits to offspring is called the Trivers-Willard hypothesis. It seems to hold true.
'In studies, Americans who are rated 'very attractive' have a 56 per cent chance of having a daughter for their first child, compared with 48 per cent for everyone else,' says Miller and Kanazawa.
Criminals and brilliant people are similar in terms of age and productivity.
Scientists have discovered an age-crime curve. Risky behaviour, like stealing, is more prevalent in youth. This impulse increases throughout adolescence, rapidly declines throughout the 20s and 30s, and plateaus during middle age.
Psychologists have found this same age/behaviour curve among brilliant artists and businessmen. They accomplish more at a young age, then they plateau. Miller and Kanazawa use Paul McCartney and Bill Gates as examples.
Bill Gates formed Microsoft when he was young. Since then, he hasn't created anything earth-shattering. Paul McCartney wrote most of his hit songs in his early days. He still writes songs, but none of them have been as successful as the ones he wrote in youth.
This age curve, too, has to do with sex and competition.
'Both crime and genius are expressions of young men's competitive desires, whose ultimate function in the ancestral environment would have been to increase reproductive success,' Miller and Kanazawa write.
'Men have had to conquer foreign lands, win battles and wars, compose symphonies, author books, write sonnets, paint cathedral ceilings, make scientific discoveries, play in rock bands, and write new computer software in order to impress women so that they will agree to have sex with them. Men have built (and destroyed) civilisation in order to impress women, so that they might say yes.'
Mid-life crises are common among men, but Miller and Kanazawa say it has nothing to do with age.
Well, not their age anyway. It has to do with their wives' ages and menopause, which marks the end of fertility.
'When a man buys a shiny-red sports car, he's not trying to regain his youth; he's trying to attract young women to replace his menopausal wife by trumpeting his flash and cash,' say Miller and Kanazawa.
Bill Clinton's infidelity and Tiger Woods' many mistresses shouldn't have been shocking, Miller and Kanazawa say.
'Men strive to attain political power, consciously or unconsciously, in order to have reproductive access to a larger number of women. Reproductive access to women is the goal, political office but one means.
'...To ask why the President of the United States would have a sexual encounter with a young woman is like asking why someone who worked very hard to earn a large sum of money would then spend it,' they write.
It's hard to be a woman in a man's world.
But Miller and Kanazawa say sexual harassment is just a non-sexist mating strategy.
'Abuse, intimidation, and degradation are all part of men's repertoire of tactics employed in competitive situations. Before women entered the workforce, men harassed each other.
'In other words, men are not treating women differently from men.'
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