sexual variety is inversely proportional to happiness.... cheating husbands and wives take note

From Hollywood to college campuses, many assume that sex is always great, and sexual variety is even better.

This assumption actually has a name: the “Coolidge Effect,” named after the 30th president of the United States. The story (probably apocryphal) begins with Silent Cal and Mrs. Coolidge touring a poultry farm. The first lady noticed that there were very few roosters, and asked how so many eggs could be fertilized. The farmer told her that the virile roosters did their jobs over and over again each day. “Perhaps you could point that out to Mr. Coolidge,” she told him. The president, hearing the remark, asked whether the rooster serviced the same hen each time. No, the farmer told him — there were many hens for each rooster. “Perhaps you could point that out to Mrs. Coolidge,” said the president.

The president obviously figured these must be happy roosters. And notwithstanding the moral implications, the same principle should work for us. Right?

Wrong. In 2004, two economists looked into whether more sexual variety led to greater well-being. They looked at data from about 16,000 adult Americans who were asked confidentially how many sex partners they had had in the preceding year, and about their happiness. Across men and women alike, the data show that the optimal number of partners is one.