

Divorces regularly peaked during and around the fourth year after wedding. Nevertheless, there was no denying it: Among these hundreds of millions of people from vastly different cultures, three patterns kept emerging. Indeed, in a 2007 Harris poll, 47% of American respondents said they would depart an unhappy marriage when the romance wore off, unless they had conceived a child. Interestingly, this corresponds with the normal duration of intense, early stage, romantic love - often about 18 months to 3 years. Americans tended to divorce between the second and third year of marriage, for example. But in country after country, and decade after decade, divorces tended to peak (the divorce mode) during and around the fourth year of marriage. I regularly got up around 5:30, went to a tiny desk that overlooked the deep woods, and poured over the pages I had Xeroxed from the United Nations Demographic Yearbooks. My intellectual transformation came while I was pouring over these divorce statistics in a rambling cottage, a shack really, on the Massachusetts coast one August morning. My mission: to prove that the "seven year itch" was a worldwide biological phenomenon associated in some way with rearing young. So I began to cull divorce data on 58 societies collected since 1947 by the Statistical Office of the United Nations. If each departed after about seven years to seek "fresh features," as poet Lord Byron put it, both would have ostensibly reproduced themselves and both could breed again - creating more genetic variety in their young. Planned obsolescence of the pairbond? Perhaps the mythological "seven-year itch" evolved millions of years ago to enable a bonded pair to rear two children through infancy together. So I had long suspected this human habit of "serial monogamy" had evolved for some biological purpose. And where they can divorce - and remarry - many do. Yet, almost everywhere people have devised social or legal means to untie the knot. Moreover, most human beings around the world marry one person at a time: monogamy.

And when I looked at United Nations data on 97 other societies, I found that more than 90% of men and women eventually wed in the vast majority of these cultures, too. Some 90% of Americans marry by middle age. When asked why all of her marriages failed, anthropologist Margaret Mead apparently replied, "I beg your pardon, I have had three marriages and none of them was a failure." There are many people like Mead.
