A recent scientific study has shown that there is a particular gene, present in two out of every five men, that makes them less likely to form a lasting monogamous relationship. So, certain men are biologically predisposed to cheat. Infidelity is in their DNA.

Who is funding this study? Probably a promiscuous billionaire who got caught by his wife and thought it wouldn’t cost him as much in alimony if he had a scientist to back up what women have known for ages.

We don’t need to unravel the double helix to know men are programmed.

But if there’s truly a genetic link, I would want a screening test. Think of all the time it would save me asking questions. Where were you? Who did you have lunch with? What did you order? All potential boyfriends or husbands would be screened with the sexual fidelity test ahead of time. Cotton swabs will be flying off the shelf.

Not that I’d trust the test. It won’t be a 100%. They never are that accurate, so there’s still room for suspicion. Precautions will have to be taken. People with fair skin need a high SPF lotion and stay out of the sun to avoid melanomas. Will men with this gene have to stay out of Las Vegas?

The downside of the test would be if a guy doesn’t have the gene and cheats anyway. What does that say? Just that he’s bored with you.

Even if they got tested though it wouldn’t matter. A lot of women will overlook the results. They’ll still find a way to make it their fault. I can hear it now: “Maybe I mutated the gene and it kicked in.”

Other women will use it as an excuse to become more invested. They’ll believe they can change him. They’ll try to figure out what triggers the genetic impulse so they can block it. Since there are varying degrees of infidelity it will become a project. Is he a chronic philanderer? Or is it seasonal? Is it a one-off and he’s plagued with guilt? Or is it just his way to exit a relationship. As long as there’s biology involved, women will find a way to forgive.

They only conducted this test on men because the hormone it acts upon plays a larger part in their brain than it does in those of women. So if science can prove that men have it in their DNA to be distant, can it explain why women have it in their DNA to be drawn to emotionally unavailable men? Perhaps there are certain women who have an acceptance gene. It’s in their DNA to tolerate bad behaviour.

One interesting point is that research has also shown that men who have the infidelity gene have a natural abiliity to get round a woman’s defences and into her apartment. The top five were:

1. Can I come in and use the loo? It’s hard to say no to that. No, I’d rather you pee in your pants?

2. I’m thirsty – can I have a glass of water? That too. He could be diabet ic. Or dehydrated.

3. Do you mind if I leave my computer inside so I don’t have to carry it around? I don’t want him to get an ache in his shoulder – what would I cry on?

4. Is it okay if I check the football results? Saying no to that is like denying a man oxygen.

5. I need to sit down for a minute – on your bed. Quickly followed by: I promise nothing will happen, we can just cuddle. How do we resist the cuddle line ?

What women need is a detection gene. It releases a hormone that repels untrustworthy men. If some men are programmed to cheat then women need a biological imperative to avoid them.

For more from Ariel Leve, see www.timesonline.co.uk/arielleve

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