10 Things You Need to Know Before You Accuse Your Partner of Cheating

1. Sometimes there is another explanation for a person losing 10Ib, working late and losing interest in sex. I just don't know it.

The Infidelity Detectives

Peter Jones was taking out the rubbish one evening when he noticed a scrap of paper caught at the bottom of the bin. “It was part of a torn email,” he says. “Suggestive words, like 'horny’, jumped out at me.” Jones didn’t leap to conclusions, but mentioned it to his wife. She was furious and told him not to be stupid. She swore it was a friend “having a laugh”.

Her over-defensive reaction gnawed at him. Within a day of finding the email, Jones had tapped “infidelity” into Google and was talking to Steve Grayson of the Infidelity Detective Agency, a Hertfordshire-based team of private investigators into matrimonial cases.

The Young and the Restless

In 2006, about 19% of married men and 13% of married women under the age of 30 said that they had been unfaithful to their spouse. Do those numbers sound high? They certainly are if we compare them with the results of a survey 15 years before, when the respective numbers were roughly 13% and 11%. A "mere" two-percentage-point increase for women and a six-percentage-point increase for men may not sound like much, but to put it another way: Between 1991 and 2006, the numbers of unfaithful wives under 30 increased by 20% and husbands by a whopping 45%. These numbers come from a study conducted by David Atkins of the University of Washington Center for the Study of Health and Risk Behaviors. Mr. Atkins, who reached these conclusions by breaking down data from the National Opinion Research Center's General Social Survey, presented his findings at the Association for Behavioral and Cognitive Therapies conference in Orlando earlier this month.