Type "infidelity" into a Google search and you will find countless sites devoted to supporting victims of affairs as well as aiding them in discovering their partner's betrayals.
Interestingly, more and more of these sites are dedicated to understanding why women cheat and how their partners can catch them. Throughout history, men's infidelity has often been expected--even the notoriously devoted Napoleon had many lovers other than his beloved Josephine. Such expectations were rarely extended to women, despite the fact that many did keep secret lives, usually because once they were discovered or became pregnant at a suspicious time they faced harsh repercussions.
Recent statistics, however, show a rise in female infidelity. In North America up to 37 per cent of men and 22 per cent of women admit to having affairs. Many experts believe that the percentage of women having affairs should be higher, but remains stunted as many women are unwilling to disclose their dirty little secrets.
According to counsellor Janis Abrahms Spring in After the Affair, affairs affect one of every 2.7 couples. Ten per cent of extramarital affairs are one time only, 10 per cent occur more than once, but last less than a month, 50 per cent last longer than a month but less than a year and 40 per cent last two or more years. Few extramarital affairs tend to persist longer than four years.
Over the years, interest in this field has grown, likely paralleling the ever-increasing divorce rate in North America. Few however have been able to pinpoint exactly what causes infidelity, often weakly accusing psychology. Dr. Martie Haselton holds physiology accountable, believing she may have found a reasonable explanation for why women stray or experience feelings of wanting to stray. A study published in the journal Hormones and Behavior indicates that the fertility cycle is a likely determinant. Researchers found that women were more likely to flirt with other men when their chance for getting pregnant was at its highest.
Haselton had 38 college women fill out a daily diary of their sexual interests and feelings. The majority of the women had a significant other or husband. When the women neared their time of ovulation, they reported feeling more attractive and more interested in meeting men, even if they were already in a relationship. This particular finding interestingly coincides with some estimates that about two to four per cent of pregnancies are the result of a one-time fling or affair.
So while a woman may fall for the nerdy type, her reproductive urges favor the masculine, regardless of whom she may be involved with.
"Women have a biology that can lead them to stray," says Haselton "These urges served a purpose in ancient times, when a man's scruffy good looks conferred an evolutionary advantage to a woman who wanted the strongest offspring possible."
Haselton's study is no excuse for infidelity, and claiming that ovulation took the wheel will not stand as a reasonable defense to any betrayed partner. However, it is another reason for us to take the time to understand our bodies and biological processes. If you are experiencing a strong desire to stray from your current relationship, examine when and under what circumstances these feelings occur before you embark on something that you and your partner may regret.