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We all know one, a bloke who lives his romantic life by the motto "treat 'em mean, keep 'em keen".
And the most puzzling thing about him is that he does indeed seem to keep them keen. Despite his complete lack of chivalry and a history of messing women around, they still seem to be queuing up for his attentions.
In other words, he's a living embodiment of the old cliché that women love a bad boy. Here's why science says that might be so, and how even good guys can get a piece of the action.
Do women really want bad boys?
Studies suggest that the answer is, in some cases, yes. One study found that men who display a "dark triad" of traits - narcissism, thrill-seeking and deceitfulness - had more sexual partners than those who didn't.
And according to behavioural psychologist Jo Hemmings, some women like bad boys precisely because they're mad, bad and dangerous to know.
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Some women are attracted to thrill-seekers, studies suggest
"There can be something extraordinarily tempting about bad boys," she admits. "It's partly the forbidden nature of it all - the rebel in women that still deserves to be unleashed from time to time. Bad boys keep us on our toes, can't be taken for granted and deliver the sort of fun and excitement that might be lacking in the more conventional, reliable guy."
Bad boys are fun
According to Hemmings, bad boys are "often passionate, unorthodox in their lifestyles and couldn't give a toss what anyone else thinks". And this, she thinks, is just what some women are after, quite a lot of the time.
Because if they don't really care what anyone else thinks, bad boys will be spontaneous, rule-breaking and experimental - in and out of the bedroom. They might be moody, unreliable and shallow, too, but at least life will never be dull. That's a large part of the bad boy appeal.
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Fun-loving men are trouble-makers, but women enjoy their company
It's also true that bad boys represent a challenge, but one with a very satisfying reward. If they can tame a bad boy when so many others have tried and failed, it's a great esteem-booster for any woman. The attraction of a bad boy is the chance to be the only one who can bring out his inner - well-hidden - romantic side.
Women love bad boy looks
Even if most women don't really want a bloke who will cheat on them at the drop of a hat, many of them fancy a bloke who looks like he might.
That's the conclusion of one recent study, in which more than 1,000 adults were asked to rate the sexual attractiveness of pictures of the opposite sex. The women in the study tended to be far more attracted to men who looked proud or brooding than they were to happy, smiling blokes.
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Studies suggest women are attracted to broody-looking men, rather than smilers
"While showing a happy face is considered essential to friendly social interactions, including those involving sexual attraction, few studies have actually examined whether a smile is, in fact, attractive," said Jessica Tracy, a professor in the University of British Columbia psychology department, where the research was carried out.
And to women, it clearly isn't. Brooding, proud men were considered attractive, perhaps because their expression seemed to display high status. On the other hand, smiling men may have been seen as too eager to please, something that denotes lower status.
There's a caveat to all this. The women were only asked to rate the men on raw sexual attractiveness, not on their suitability for a long-term relationship. And that's worth bearing in mind.
How to become a 'good' bad boy
The message in all of this is that women fancy the bad boy stereotype, but don't want a proper bad boy for a boyfriend. They see a bad boy as a challenge - and the challenge is to bring out his good side.
They may want some bad boy traits without wanting the full vain, arrogant, selfish, pain-in-the-arse package. If you're a good guy - and we assume you are - you can use that knowledge to your advantage.
The Columbia study suggests that you shouldn't be too eager to please. Be friendly, interested and engaging, but don't agree with everything she says. Have an opinion, argue the point, and don't be at her beck and call.
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Be interested and engaging, but don't be at her beck and call
And if the bad boy cliché says anything, it's that we should try to be spontaneous and just a little bit unorthodox, at least from time to time. Because what Hemmings and others say the bad boy appeal really means is that women are worried about getting into a relationship rut.
They don't want steady-as-she-goes all the time. They don't want to know in advance what every weekend holds, or indeed how the next hour in bed might turn out. They want passion, impulsiveness and a devil-may-care attitude - in the right circumstances.
But they don't want the other stuff - the deception, infidelity or moodiness. In the end, science says the real bad boys lose the girl. "Take heart; most women will want a good guy with good prospects (a stable job and lifestyle) eventually," writes psychologist Dr Nando Pelusi. "Work on being independent and assertive and allowing spontaneity into your repartee. Discover your connection with someone in visceral, not just cerebral, ways."
The long game
In other words, don't try to be truly bad - even if you pull it off (which is unlikely if it doesn't come naturally) - you'll lose out in the end.
If you're a good guy, add a few bad boy traits without compromising your inner decency. Women do fancy a bad boy, but they end up with the guy who offers it all - pride, assertiveness and spontaneity certainly, but decency and fidelity too.
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