REVEALED: You can now tell how likely your partner is to cheat by the size of the family

People found guilty of cheating on their partner offer all types of excuses and reasons for their actions.

"Our marriage was already over", "I've not been happy for years", "It didn't mean anything to me" and "I was weak, drunk and lonely" are just a few.

One so-called motivation which has probably never come up is "I can't help it, I'm an only child."

Married-dating website Illicit Encounters conducted the research among its member, looking to see which sort of person actively seeks an extra-marital relationship.

According to the site, it's children with no siblings who are most likely to cheat on their partners as adults.

So much so, they make up the biggest group on the site, with 34 per cent of members reporting they are an only child.

The next "most likely to cheat demographic" are, apparently, eldest children, with 28 per cent of the site's cheaters being first borns.

As for why only children are more susceptible to cheat, Christian Grant, the site's spokesperson told The Sun :

"It's well-known that an only child can experience the feeling of immense loneliness in their childhood, and that comes back to haunt them in their future relationships.

"Having been starved of attention for so long, it's something that they find themselves in desperate need of.

"This manifests itself quite clearly when someone's partner works long hours or travels frequently for work; the alone time for an only child just won't do, so an affair is the perfect short-term solution."

This is in stark contrast to middle children, who emerged as being the least likely to cheat.

On this, Grant added: "On the other end of the scale, a middle child is surrounded by loving parents and siblings.

"They don't grow up with the same need of love and affection, but they're also more than comfortable during moments of isolation."