Why are men such dicks? (2014)

Men cliff diving
‘Death … or Gloria!’

‘This macho advantage of speed, strength and fierceness can be exaggerated by females’ tastes. As half of a female’s fate is tied up in her sons, she may have evolved to prefer males who are stronger, faster and who have a greater appetite for risk, since they will be more likely to father sons with those advantages.’
Susan Pinker, The Sexual Paradox

‘Do you want to be safe and good, or do you want to take a chance and be great?’
Jimmy Johnson, American football coach

Up ’til now, I’ve couched most of my arguments in terms of alpha males and betas, of bad boys versus nice guys; of men’s preference for looks compared with women’s for status and resources. But every now and then, it’s useful to look at things through a different-coloured lens. And if you consider the typical behaviour of the two sexes, one of the most salient differences between them is in their attitude to risk.

Men love danger. Women don’t. At least, the willingness to undertake dangerous activites is far more common, and far more pronounced, in males than it is in females.

Men drive faster. They die more frequently in accidents. They are more likely to run red and amber lights and less likely to wear a seat belt. They get into more fights, drink more, smoke more, gamble more, experiment with drugs more, and engage in more hazardous activities like boxing and Base jumping. They tend to invest rather than save; and as children, they’re more likely to play rough than play “nicely”. (These tendencies, in fact, account for most of the difference in life expectancy between the sexes – currently 83 for women in the UK and 79 for men. It’s not so much that men are less hardy; once they’re past a certain age, they live about as long as women. Most of the disparity is down to the fact that so many men die unnaturally young, through alcoholism, violence, smoking-related illnesses and accidents. Read this Scientific American article for more.)

The vast majority of scientific research in this area agrees that men are more prone to risk than women. Here are just a few examples: Sex Differences in Judgment Processes (Wallach & Kogan, 1959); Gender Differences in Risk Assessment: Why Do Women Take Fewer Risks than Men? (Harris, Jenkins and Glaser, 2006); Both Risk and Reward are Processed Differently in Decisions Made Under Stress (Mather and Lighthall, 2012); and Geoff Trickey and So Yi Yeung’s 2012 study for the Psychological Consultancy Limited, which concluded that men are twice as likely to take risks as women. “From the scale of these findings, we concluded that risk-taking must be a distinctive feature of gender,” the authors wrote.

A recent flurry of studies have challenged this view – but all have major flaws. A 2008 survey for the Simmons School of Management, for example, claimed that women engage in high-risk behaviours just as often as men. However, its female subjects were all leading business managers. These women were not remotely representative of their sex; they were women who must already have taken significant risks in order to get where they were. (What are these geniuses planning next? To prove that women are taller than men by measuring the 100 tallest women in the world?) A 1998 study by Lori Embrey and Jonathan Fox made a similar methodological mistake; it found that high-earning women were more likely than other women to put their money in the stock market … Well, duh. How do you think they became high earners in the first place?

When a report by Germany’s Bundesbank was published in 2012, the headlines ran, “Women take bigger risks” – but what the report actually found was that the presence of women in senior roles spurred their male colleagues to take greater risks, which is not the same thing at all (more on how women affect male behaviour below).

One paper, which actually stands up to cursory scrutiny, came to a more nuanced conclusion: that men and women react differently to different kinds of risk. Men, it found, were more likely to take physical and financial risks, while women were more open to social risks (starting a new career, or sticking up for someone who’s been bullied). But even here it’s worth bearing in mind that women can afford to lose social capital more than men – it is less useful to them in the first place (since it’s not a quality men especially value in a mate), and can be won back more quickly.

Why should things be this way? As ever, there are two competing schools of thought: those who think that attitude to risk is shaped by cultural forces (role models, education, tradition), and those who believe its basis is biological.

The first strike against the cultural argument is that males take more risks than women in every culture on the planet, many of which, until recently, had had little or no contact with one another for millennia. If a behaviour is divided along gender lines the world over, it would require a gargantuan coincidence for each culture to have settled on the arrangement separately.

The second is that it’s hard to see what reasons there could be for such a state of affairs. Why does it make sense to encourage boys to be daredevils but to warn girls to play it safe? In every civilisation in the history of man? Most parents actively try to deter their daughters and sons from reckless acts. The majority of boys go off the rails despite their parents’ pleas, not because of them. How many parents do you know who instruct their pride and joy to take drugs, clamber around building sites and ride motorbikes?

Now, for most of the rest of this post, I will be talking largely about mankind historically – ie about the conditions that prevailed, and the evolutionary adaptations that came about in response to those conditions, prior to the modern era. But much of it will still be relevant today. Civilisation has only existed for a few thousand years, and man spent far more time living in caves and roaming the savannah than he has done in cities and villages. Evolution simply hasn’t had time to do much since the discovery of agriculture; fundamentally, we’re still the same creatures that hunted and gathered and wandered and murdered 20,000 years ago.

So if men’s greater propensity to take risks is biological in origin, why did it come about? You might be expecting some simplistic guff about how men had to hunt, while women gathered and nursed the children, but it’s a little more complicated than that.

For reasons I’ve described before, to do with differences in sex drive, the reduced availability of women owing to pregnancy and childcare, the scarcity of eggs relative to sperm, and the amount of time women must invest in reproduction relative to men, females throughout the animal kingdom are the gatekeepers of sex. That is to say, it tends to be males who approach females, and females who decide whether or not to proceed with mating (or whether to make mating easy for the male). The few exceptions to those rules are species, such as seahorses, where the male plays a significant parenting role.

Just think. Even today, in this largely liberal, egalitarian world, it’s still almost always the man who makes the first move in courtship. In bars, on online dating sites, even on Tinder – where anyone can proposition anyone else in a trice, in complete safety – it’s still men who initiate contact. (Some women can and do take the lead, but they’re in a tiny minority, and the objects of their advances are often put off.)

This leads to two distinct but closely related phenomena: female choice and male competition. Under the female choice system, the purest form of which is courtship display, females observe males, then select the one they consider the prime specimen, based on criteria such as size, speed, plumage, fitness and freedom from parasites. Male competition works a little more bluntly: the blokes fight, and the winner takes the spoils.

It’s not clear which system has played the greater role in the human story. There is certainly an element of male competition, as fights over mates still take place to this day, particularly in “uncivilised” tribes and commuter-belt pubs, and men are on average a little bigger than women, which in most species indicates competition. And female choice certainly contributes, as men generally approach women, and women say yay or nay, and courtship display among men – showing off expensive cars and watches, general jostling for status – is widespread. (Scientists have recently acknowledged the existence of female competition and male choice, but these seem to play a minor role.)

It doesn’t really matter, because the result is the same. Whether they are chosen or champions, some males win, big, while others lose – utterly. Polygyny is far and away the most common mating system in the animal kingdom; according to one estimate, 20% of the males on the planet account for more than 90% of all matings. Although things aren’t quite so skewed in modern humans, the evidence is that polygamy has been rife in our history too.

(If you’re not prepared to take my word on that, read my post – the relevant bit’s at the end – on ancestor bias, which shows that twice as many women have reproduced as men and gives some more snappy stats on variance in reproduction.)

For women, meanwhile, there is no ultimate victory or defeat – except in terms of the quality of the partner they end up with. Barring horrible misfortune, most of them will reproduce.

And how do men win or lose? By taking a risk. Whether they need to take out the competition, or to outwit them, or to outdo them in more indirect fashion in order to achieve the status and resources that will attract a female (or several) to them, they have to take the bull by the horns. In his book on evolution and sex, The Red Queen, Matt Ridley says: “Men have evolved to live dangerously because success in competition or battle used to lead to more or better sexual conquests and more surviving children.”

If you have any lingering doubts as to why men act like idiots, consider the following experiment conducted at the University of the Bleeding Obvious – sorry, Queensland – in 2010. Professor Bill von Hippel sent observers to watch skateboarders at a nearby skate park. They noted that the young men took more risks when they were being observed by an attractive female experimenter than when the observer was male. This increased risk-taking led to more spectacular manoeuvres (and more crashes) in front of the female observer.

Let’s look at a couple of graphs to help us think around this for a moment.

Men risk graph

Women risk graph
Click on either image to enlarge.


a) You’ve probably noticed the absence of numbers. These graphs aren’t supposed to be representations of any actual figures, just visualisation tools.

b) As with most of the text above, these are intended primarily as depictions of the forces acting on prehistoric humans – but probably still carry quite a lot of relevance today.

c) The female graph should ideally be a lot slimmer than the male one – ie the variance in payoff should be smaller – but it took me ages to draw those damn things and I can’t be arsed to do them again.

These graphs plot risk (x-axis) against reward (y-axis) for every human being who has ever lived. Everyone falls somewhere in the shaded area, either on the male or female grid. The x-axis represents a combination of the size and number of risks that an individual takes in a lifetime, so zero equals no risks at all, while high values of x mean many slightly risky acts (or perhaps several extremely risky ones). It’s impossible to take fewer than zero risks, so there’s nothing plotted for x < 0.

The y-axis, payoff, is, if you like, genetic legacy, or success in the mating market. You might say “Number of healthy offspring that survive to reproductive age”. The negative values on the y-axis don’t have any real meaning; essentially, a value of zero on the payoff axis means “died without reproducing”, and every negative score means “died prematurely trying”, which from an evolutionary standpoint is no worse than not trying and living childless to a ripe old age, but by most standards is less of an achievement. Thus, the larger area below x = 0 on the men’s graph reflects the greater number of deaths in combat, in accidents incurred during showing off, and from depression-related illnesses, suicide, etc.

The reason for the spread in values of x for values of y – well, that’s essentially fate, and/or skill. Every risk has (at least) two possible outcomes: success, and failure. So two different men, A and B, could undertake a task with the same level of risk – say, fighting each other over a woman – and while A is richly rewarded for his risk with victory and offspring, B dies. Man C, meanwhile, takes no risk at all, which allows him to live a peaceful life, but means that he fails to win any status or otherwise impress a mate, and he too dies childless.

A man must, if he is to secure genetic immortality, at the very least, approach one female, which carries the risk of attack from a rival (or the female). And most of the time he will probably have to do a lot more than that, such as prove himself as a reasonable hunter and secure himself halfway decent status within the tribe.

The story on the women’s graph is rather different. Woman A and B both take risks of equal magnitude; one succeeds, one fails … but the variance in outcomes is smaller. Success does not bring such great rewards, because a woman cannot have as many children as a man can. Moreover, look at Woman C. She takes no risks at all, but still receives a payoff. She never has to take a risk, because the onus is on men to approach her, to defeat rivals for her, and to persuade her of his own merits. Also, because women have historically done the lion’s share of childcare, the more children a woman has, the less it pays her to take risks, because she endangers not just her own life, but the lives of all the children she has already invested so much time in.

So whichever way you slice it, women stand to gain less from taking risks than men do. In fact, on the whole, taking risks is generally a pretty terrible idea for a woman – while for a man, it’s essential.

With such unequal forces acting on the two sexes over such long periods of time, it would be astonishing if there were not some evolutionary response.

To recap, any males who do not take risks are immediately removed from the gene pool. Some of those who do take risks die, or otherwise fail, and are also eliminated. However, those who take risks and succeed potentially earn a huge payoff: they will have large numbers of mates and even larger numbers of offspring (look up the number of living descendants of Niall of the Nine Hostages, Charlemagne and Genghis Khan). If there is any genetic component to risk-taking, it will be passed on, in spades.

Of course, initially, if the genes concerned are “sex-blind”, as most are, this bold spirit will be passed on to the great conqueror’s daughters, as well as his sons; but as we’ve seen, risk-taking in women is actively harmful to their genes’ chances of survival. Thus we now have two contrary selection pressures: for more risk-taking in men, and less in women. But if any sex-biased element of the inheritance of risk should arise, this would run rampant. That is, if there is something heritable that promotes risk-taking in men but not in women, it will spread through the population like a video of a burping hamster.

And blow me down if just such a mechanism doesn’t exist. There is no such thing as a “gene for risk”, but there are genes that govern the production of testosterone, which occurs in far greater quantities in men than in women. And testosterone, among a multitide of functions, is the risk hormone par excellence.

In a 2008 Harvard University paper, “Testosterone and financial risk preferences”, Coren L Apicella et al discovered that risk-taking (of a financial nature) correlated positively with salivary testosterone levels. A similar study in 2009 by Sapienza, Zingales and Maestripieri came to the same conclusion. Testosterone has been shown to enhance the motivation for competition and dominance, to reduce fear, to change the balance between sensitivity to punishment and reward, and is strongly associated with risky behaviour such as gambling and alcohol use.

My own experiences illustrate the point pretty well. When I’ve done crazy things in the pursuit of love – even borderline illegal ones – I’ve often succeeded beyond my wildest dreams (although there have of course been setbacks). Whereas each time I’ve played it safe and done nothing, relying on the woman, or fate, to intervene, I’ve ended up empty-handed. I can count the number of times a woman has made the first move on me on the fingers of one hand. One clock hand.

What does all this mean? What am I getting at? Well, if there’s an air of boo-hoo to this article, it’s unintentional, because pity is not my aim. Nor am I seeking somehow to blame women for a situation that has clearly come about without premeditation on anyone’s part. But I do think this line of thought might suggest an explanation for the persistence of inequality in the workplace. If men really are more predisposed to take risks, then they are always going to apply more quickly for promotions, to take bigger gambles with company finances, to ask for pay rises more aggressively, and so on. Many of them are going to fail – but some will succeed, and they will perpetuate the inequality no matter what anti-discrimination laws are passed.

Just to be clear, I am not trying to justify the status quo. I hate the status quo as much as the next man (assuming the next man isn’t a cigar-chomping, sexist, Daily Mail-reading, cheating, Tory alpha male). But I believe that if we know the true reasons why things are the way they are, we stand more chance of improving them. The answer might lie in revising parenting and education to compensate for the “risk deficiency” in the female psyche; perhaps we need to re-engineer social and professional systems – and hopefully, eventually, attitudes – so that they reward skill, rather than risk-taking per se. Or maybe we could just give women testosterone jabs.

My suggestion would be to tackle the “risk excess” in men – to stop rewarding reckless behaviour. Principally by ceasing to sleep with the culprits. Why are men such dicks? Because their fathers were dicks, and someone shagged them. You might not need to keep campaigning for full equality, ladies; the matter just might be in your hands.

Lessons in love (1981)

Fonda, you have much to answer for.
“Will it come like a change in the weather?
Will its greeting be courteous or rough?
Will it alter my life altogether?
O tell me the truth about love.”
WH Auden 

“So, Andy,” said Dad with a twinkle. “How do you fancy staying up late tonight?”

I was 11 years old. Bedtime on school nights was 8pm, 10 at the latest at weekends. To be allowed to stay up after Mum went to bed was a treat on a par with a personal visit from Tom Baker.

The reason for this break with protocol, it emerged, was that Dad wanted me to watch a film with him: Barbarella, the 1968 comic-book adaptation starring Jane Fonda as an interstellar explorer with an uncanny knack of losing her clothes. I enjoyed the film more for the robots and monsters than for Jane’s wardrobe malfunctions, although the semi-nudity did coincide with some stirrings which, at the time, I put down to Mum’s shepherd’s pie.

It was years before I worked out what was going on that night. Roger Vadim’s kitsch sci-fi romp was, I realised, the sum total of my parents’ efforts to explain to me the myriad complexities of human reproduction. No awkward birds-and-bees talk, no 1950s government information booklet “accidentally” left by my bedside; just a scantily clad spacewoman being pecked to death by budgerigars.

The state didn’t do much better. We had one sex education lesson, at the end of my second year, which consisted of two indecipherable diagrams, some vague mumblings about Aids, and a five-minute video of a gruff-looking German woman unrolling a balloon over a stick. It was like teaching Mandarin from a takeaway menu. There was nothing about feelings; no clue as to whether this was roughly average size for a stick; and most importantly, no pointers on how to persuade the German woman to touch your stick in the first place.

The internet and self-help literature were years away. If I’d had any brothers or sisters, I might have gleaned the odd snippet by putting my ear to their bedroom door; as it was, the only scraps of information available were the eye-boggling fisherman’s yarns of the playground and the odd scrunched-up jazz mag abandoned in the woods. And with coordinated teams of torch-wielding teenagers combing for them in overlapping eight-hour shifts, those were hard to come by.

But I wasn’t too worried. Everyone else seemed to get by without an instruction manual. Sex obviously comes naturally to humans, as it does to the animals. I would instinctively know the right thing to do when the time came. Wouldn’t I?

♥ As you read this, a million people are having sex. (The World Health Organisation estimates that 100 million sex acts take place every day, and as the average duration of intercourse is 7 minutes, at any one moment, there are about 500,000 couples making whoopee.)

And when we’re not doing it, it’s never far from our minds. The oft-touted statistic that men think about sex every nine seconds is a myth, but various studies put the figure at anything between several times a day and once a minute. It’s reckoned that there are about half a billion pages of porn on the internet, and sexual images are everywhere, in newspapers and magazines, on TV and advertising billboards.

Yet for a species seemingly so obsessed with sex, mankind has been remarkably slow to learn about it. The derisory state of sex education in the 1980s isn’t actually that surprising when you consider that sex and love and relationships, were, until roughly that time, a mystery to everyone. 

Whether it was because sex was taboo, or because we felt the subject somehow beneath our attention – everyone knows how to have sex, don’t they? – there was practically no research into the field until the alarmingly recent past. In 1982, John Farley, in his book Gametes and Spores, wrote: “Sex remains almost as complete an enigma today as it was 300 years ago when Dutch microscopists discovered minute ‘animalcules’ swimming about in human seminal fluid.”

Sure, we’d figured out the nuts and bolts – but even they were a long time coming. Sperm (as opposed to semen) were only discovered in 1677, and it was another 150 years before anyone clapped eyes on a human egg. Until the mid-18th century, most scientists still held to the ancient Greeks’ theory that male semen contained complete human beings, and women were just a sort of incubator.

Things didn’t move much quicker in the early 20th century. In 1933, Sigmund Freud advised those who wished to learn about women to “turn to poets, or wait until science can give you deeper and more coherent information”. Alfred Kinsey published his reports on human sexual behaviour in 1948 and 1953, and while they revealed a lot about what people did, they offered no explanation of why they did it. In fact, we’d split the atom, invented the laser and landed on the moon before anyone had even begun to address many of the fundamental questions of sex.

Why do we have sex? Why does attraction fade? Why do people cheat? Why are there so many female prostitutes, and so few heterosexual male ones? Why is it always men who propose? Why are so many women attracted to men who treat them badly? Why do you often see beautiful women with ordinary-looking men, but never the opposite? What is beauty anyway? Why is it more acceptable for men to sleep around than women? Why is it easier to meet a partner when you already have one? Why are there so many single mums and so few single dads? What’s so attractive about a sense of humour? And what, exactly, is chemistry?

Many of these questions hadn’t even been asked by the time I was born, and none of those that had had received satisfactory answers.

The first breakthroughs to cast light on these issues came in the 1970s – although they were building on a theory that was more than 100 years old.

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Helicopters in the stomach (1983)

I got the racer two weeks later.
“He was so afraid of girls that he made a secret study of them. But the more he studied them, the more he feared them.”
Opening dialogue card, Harold Lloyd’s ‘Girl Shy’, 1924

Until that Monday, I minded my own business. I went fishing for minnows at the weir with Heath and Jez. I threw myself into my history homework with what I would eventually realise was borderline pathological zeal. I got thrashed at contract whist by Mum and Dad and Nana Martin; skidded down the grassy slopes of Barbury Castle on old cardboard boxes; counted down the hours to the next episode of Doctor Who. In short, I enjoyed innocent, uncomplicated passions that I thought would last for ever.

Until that Monday.

She wasn’t what you’d call classically gorgeous. In fact, no one else seemed to have noticed her. She was quiet, slim, average height, with hypnotic, sparkling grey-green eyes, hair like burnt Shredded Wheat, and what seemed to be a giant steel girder attached to her face. 

Yes, she wore a dental brace; one of those terrifying Disneyland monorail affairs going all the way round her head. But every time she smiled – even through all that scaffolding – my heart tried to jump out through the top of my head. 

For the first few weeks, I contented myself with gazing across at Kerry in Geography, ignoring the teacher’s dronings about the formation of terminal moraines and wondering how it was that no one else could hear the tom-tomming of my heart and the Lynx attack helicopters circling in my stomach. Before then, I had always been the first to raise my hand when the teacher asked a question. Now I waited for my beloved to raise hers, in the hope that her sleeve would slip a little and expose just a couple more inches of heavenly forearm. 

With every passing week, the helicopters grew louder and the throbbing more intense – but I still had only the dimmest notion of what they meant. There was a rumour that Steven Foster, a loud, scruffy boy in my tutor group, had been seen holding hands with Lizzie Stutters, a skinny, spotty girl in the year below. And I’d heard other children talk about “fancying” girls – but somehow the word “fancy” didn’t quite cut it. After all, when people say, “I fancy a cup of tea”, it means they’d quite like a cup of tea, but it won’t be the end of the world if they don’t get one. And I knew it would be the end of the world if I didn’t get Kerry. 

So, the day we broke up for half-term in February 1983, during afternoon break, I sought out Sharon Penney. Sharon was no great shakes at English or Maths; but when it came to Other People’s Business Studies, she was top of the class. 

She was uncooperative at first, but an offer of two lots of maths homework soon loosened her tongue. Kerry lived on the main street in Broad Hinton, she said, a village five miles from mine. 

So three days later, trembling with excitement and dread, I put on my only remotely trendy pair of trousers, gave my bike a thorough clean, and set off. 

Five miles wouldn’t normally be much to ask of an able-bodied 13-year-old on a bicycle. But there were complicating factors. First, my chariot wasn’t exactly state of the art; it was a three-year-old Raleigh Grifter, a sort of bulky proto-BMX with none of the BMX’s ruggedness or manoeuvrability. Second, I wasn’t entirely sure how to get there. And third, it was -7 degrees C, and we were well into our third consecutive day of heavy snow. But somehow, two hours later, a pitiful snowman on wheels dismounted outside 128 Post Office Lane. 

After I’d brushed off all the powder, I took a minute to catch my breath, and thought about what I was doing for the first time. I liked Kerry, but would she like me? I’d never really considered whether I was good-looking or not. Nana Bodle always called me her “handsome boy”, but she was biased. I was skinny. And ginger. And, according to Steven Foster and his mates, a nerdy swot. On the other hand, I was a nice boy from a nice family – well spoken, fairly intelligent. And I was wearing my trendy trousers.  

Oh well. There was only one way to find out. I screwed up my eyes and knocked. 

After 20 agonising seconds, a young girl – a good two years younger than the one I was expecting – answered the door. 


“Um… h-hello.” With the cold and the nerves, I was juddering like an arrow in an archery target. 

“What do you want?” Very self-possessed, was this 11-year-old. 

“Is this Kerry’s house?”

The doorman sneered. “Yeah.”

I had rehearsed everything up to this point. But it now dawned on me that I had no idea what was supposed to happen next. Should I ask to come in? Should I ask if Kerry wanted to come out? What if she was busy? My mind was as blank and skiddy as the country lanes I’d just cycled over. 

So I mumbled, “OK, thanks,” jumped back on my bike, and rode the five miles home. 

I’ll never know what would have happened if I’d had the courage to say something that day. But it presumably wouldn’t have involved the entire population of the school laughing at me for a week. 

♥ Charles Darwin hated peacocks. “The sight of a feather in a peacock’s tail, whenever I gaze at it, makes me sick!” he wrote to botanist Asa Gray in 1860. 

The previous year, Darwin had published Origin of Species, setting out his theory of natural selection – a theory 20 years in the making. His idea, with all that it implied for the story of the Creation, had been greeted with predictable howls of rage from the church, but its reception in the scientific community and the general public was much warmer. No one could point to anything that seriously undermined his simple, elegant argument. 

Except for the peacock. 

If Darwin was right, and all the traits of modern animals were adaptations that had evolved over millions of years to maximise their chances of survival, then what was this ridiculous bird doing strutting around showing off its elaborate, brightly coloured feathers, which are not only useless and cumbersome, but actually reduce its chances of survival by making it more visible to predators? 

In fact, natural selection struggled with sex differences generally. It couldn’t, for example, explain the southern elephant seal, the males of which are five to six times heavier than the females. It couldn’t explain deer antlers, which are good for nothing but fighting other deer with. And it certainly couldn’t explain the green spoonworm, a type of marine worm in which the male is a glorified, brainless pair of testes that spends its entire life inside the female’s genitals.

By the rules of natural selection, males and females ought (sexual organs aside) to be identical. After all, they face identical challenges: they share the same habitat and the same diet; they have the same predators, succumb to the same illnesses. Adaptations that are useful to one sex should be just as useful to the other. 

Sex, Darwin realised, was the key. The ultimate test of evolutionary success is not how good you are at surviving, but how good you are at reproducing. From a genetic point of view, it’s better to live a short life and produce some offspring than it is to live to a ripe old age and have none. 

The peacock’s brilliant plumage may work against its survival – but because big, showy tails happen to appeal to peahens, they increase its chances of mating. The same is true of the male elephant seal’s bulk, the male deer’s antlers and, in theory, the small male human’s trendy trousers. 

Darwin presented his theory of “sexual selection” in The Descent of Man, in 1871  and was roundly ignored. The biologist RA Fisher revived the idea briefly in 1930 with his book The Genetical Theory of Natural Selection, but it was another 40 years before anyone realised just how powerful a light this insight could shine on human relationships – and on human nature in general. 

The science of dating