Tad: It's official: women go for bastards.

Molly: No kidding, Sherlock.

Tad: No, I mean, it's OFFICIAL. Two scientific reports confirm it. Men who exhibit a “dark triad” of Machiavellian personality traits - narcissistic selfobsession, callous thrill-seeking and exploitative deceitfulness - have more sexual partners.

Molly: So where does that leave someone like you?

Tad: In dating no-man's-land. These “dark triad” guys ruin it for everyone. They make a woman fall in love, treat her appallingly and then dump her. When the nice guys (like me) come along, these women are unable to distinguish false flattery from my sincere emotions.

Molly: That all sounds a bit too strategic: this whole evil genius label endows men who are emotionally constipated with more glamour than they deserve.

Tad: I cannot believe you are letting these bastards off so lightly. They use and abuse your sisters for sport.

Molly: But is it sport? It all comes down to intention. Most of the bastards I know are just operating with the attention span of fruit flies. They run every affair on hyperspeed. Instead of months or years, it takes just days to get through the cycle of infatuation, acclimatisation, deflation and then procrastination, as the party who falls out of love first is terrified of disentanglement.

Tad: But why do women fall for these guys? They come with reputations as overt as the government warning on cigarettes: This man will use you and then discard you.

Molly: We fall for them because, when they are in infatuation mode, they aren't putting on an act to disguise their evil intentions. It feels real because it is real. The hard bit comes when they go off you. And the messy endings usually involve cowardice rather than cruelty.

Tad: It's OK because it isn't deliberate?

Molly: It's not OK, but I can forgive it - except when it happens to me.

Tad: I don't see why it matters that the bastard's intentions may be genuine. The effect is the same... I'm shocked you're giving them such an easy ride.

Molly: But setting out to abuse someone is so much worse. I think the really bad characters are gold-digging, status-hunting women.

Tad: No. They're not bad characters. They're businesswomen.

Molly: But gold-diggers are much more calculating - they bide their time until they can wreak maximum damage. Hurting people isn't a by-product of being emotionally crippled.

Tad: I know men who fall for gold-diggers, but it's a financial transaction. The man gets a trophy and she gets his credit card. If the guy's smart enough to make the money, he's knows what he's getting.

Molly: Did you know that London's leading divorce lawyers have been reporting bumper business from trophy wives wanting to know whether to jump now or wait for the next City bonuses?

Tad: Yeah, so the guys are left with two of their four holiday homes. They'll have a younger model next year. But the women hurt by dark triads are scarred for life. You know that line from When Harry Met Sally about wounded women operating in dog years? It's true.

Molly: The fruit flies definitely suffer less than the dogs. But what the golddigging woman does is premeditated. The men you hate so much probably can't understand why they repeat the pattern of damage because, let's face it, they're not capable of the depth of introspection required to figure it out.

Times recommends

• Pity the poor (other) woman
• It was all too easy to lose my son
• Video: How to do party make-up