Women are 'genetically programmed to have affairs'

'Lifelong monogamy does not characterise the primary mating patterns of humans,' says Dr David Buss from the University of Texas

Women are predisposed by their genetics to have affairs as "back-up plans'" if their relationships fail, according to a research paper.

Scientists at the University of Texas say they are challenging the assumption that humans have evolved to have monogamous relationships.

The team's research has put forward the "mate-switching-hypothesis" which says humans have evolved to keep testing their relationships and looking for better long-term options.

The senior author of the research, Dr David Buss, told the Sunday Times: "Lifelong monogamy does not characterise the primary mating patterns of humans.

"Breaking up with one partner and mating with another may more accurately characterise the common, perhaps the primary, mating strategy of humans."

For our distant ancestors – when disease, poor diet and minimal healthcare meant that few people lived past 30 - looking for a more suitable partner was necessary, researchers assert.

Despite anecdotal claims about cheatng, no study has shown that humans are predisposed to monogamy or non-monogamy.

A study carried out by Rafael Wlodarski and a team of researchers at Oxford University looking into infidelity found a correlation between the length of a individual's ring finger and the likelihood that they would cheat on a partner.

However, they stressed that they could not find a causal link.

Professor Robin Dunbar of Oxford University said the differences were “subtle” and “only visible when we look at large groups of people”.

"Human behaviour is influenced by many factors, such as the environment and life experience, and what happens in the womb might only have a modest effect on something as complex as sexual relationships," he said.

Dr Buss said: "Affairs serve as a form of mate insurance, keeping a back-up mate should a switch become warranted in the future.’

"A regular mate may cheat, defect, die, or decline in mate value.

"Ancestral women lacking a back-up mate would have suffered a lapse in protection, and resources."