You'd have thought there were myriad reasons why people in a monogamous relationship would cheat on each other - dissatisfaction, resentment, high libido or mere boredom.
The definition of cheating is unclear and changing all the time: research released yesterday suggested that over a third of Britons don't think engaging in sexting constitutes as cheating on a partner.
But the team behind The School of Life think they have at least cracked the reason why cheaters do what they do, and it all boils down to one simple thing - the conflict between closeness and distance.
A handy video by the YouTube channel explains using cartoons that every couple requires differing levels of both for a happy and stable relationship to persist.
On the one hand...
In a relationship that threatens to lean perilously towards
overcloseness, we can be driven to stray by a powerful urge to prove
that everything we do and are is owned by the partner
But on the other...
Too much distance reads like constant rejection... we may end up
having an affair not because we don't love the partner any more, but
precisely because we do, and yet the distance is unendurable and humiliating
To make matters even more troublesome, two people almost never enter a relationship with the same needs for distance or closeness, according to The School.
This can lead to one partner being branded 'too clingy' and the other 'too cold'
The School recommends that these labels be dropped and suggests the only thing that can be done is to have clear communication at the beginning of a relationship.
A few years back, the bestselling book The Truth About Cheating showed that 48 per cent of men who cheated cited 'emotional dissatisfaction' as the main reason they strayed - suggesting The School of Life might be onto something with this one.