Marital infidelity.

The Anatomy of Love, Helen Fisher argues that the human propensities for love, attachment, monogamy, and adultery are in part conditioned, though not determined, by evolutionary selection mechanisms which originated among early hominids and pre-hominids. Fisher speculates that "infatuation" is caused in part by an "excitant amine" called phenylethylamine or PEA and "attachment" (a subsequent and mote peaceful if not so exciting relationship) by the endorphins "calming" the fervor of "falling in love." The argument is neither reductionist not unpersuasive but questions remain as to how many married men and women in a modern industrial society, like the United States, actually indulge this pre-hominid propensity for adultery, who these men and women ate, and why the propensity may be especially pronounced in them. Results of non-random survey research would indicate that the majority of married Americans have been unfaithful to their spouses at some point. However, data collected at the National Opinion Research Center in a national probability sample indicates that 10 percent of married American women and 20 percent of married American men have been unfaithful.

Infidelity Rates

Alfred Kinsey, in his famous "reports," asserted that about half the men and a quarter of the women in his samples had committed adultery. Writing in Playboy, Morton Hunt reported that 42 percent of the white middle class men and 25 percent of white middle class women had engaged in adultery. Linda Wolfe claimed in Cosmopolitan that 54 percent of married women had at least one affair. Shere Hite concluded in The Hite Report that 72 percent of married men were adulterous. The June 1977 issue of Marriage and Divorce stated confidently that "70 percent of all Americans engage in an affair sometime during their marital life." Most recently Samuel S. Janus and Cynthia L. Janus, authors of the Janus Report on Sexual Behavior in America, have reported that a third of married American men and a quarter of married women have been unfaithful to their spouses.

All these statistics have one characteristic in common: they ate not based on national probability samples. Several even seem to be based on self-selected samples. That a responsible and cautious scholar like Helen Fisher should have to rely on articles in magazines like Playboy and Cosmopolitan for data is proof that American social science--largely because of the timidity of funding agencies--has not been able to approach human sexual behavior with all the resources of modem research techniques.

These "reports" are to responsible social science what alchemy is to chemistry, phrenology to physiology, astrology to astronomy, and magic to medicine. The authors of the reports, however sincere their intentions may be, are in objective fact charlatans if they pretend to be able to draw statistically valid inferences about the whole of American society from their samples. Let it be written in the …