That's one finding of Tim Wadsworth, an associate professor of sociology at the University of Colorado Boulder, who recently published the results of a study of how sexual frequency corresponds with happiness.
As has been well documented with income, the happiness linked with having more sex can rise or fall depending on how individuals believe they measure up to their peers, Wadsworth found.
His paper, "Sex and the Pursuit of Happiness: How Other People's Sex Lives are Related to Our Sense of Well-Being," was published in the February edition of Social Indicators Research
Using national survey data and statistical analyses, Wadsworth found that people reported steadily higher levels of happiness as they reported steadily higher sexual frequency. But he also found that even after controlling for their own sexual frequency, people who believed they were having less sex than their peers were unhappier than those who believed they were having as much or more than their peers.
"There's an overall increase in sense of well-being that comes with engaging in sex more frequently, but there's also this relative aspect to it," he said. "Having more sex makes us happy, but thinking that we are having more sex than other people makes us even happier."
Wadsworth analyzed data from the General Social Survey, which has been taking the "pulse of America" since 1972. All respondents in all years are asked whether they are "very happy, pretty happy or not too happy."
The survey has included questions about sexual frequency since 1989. Wadsworth's sample included 15,386 people who were surveyed between 1993 and 2006.
After controlling for many other factors, including income, education, marital status, health, age, race and other characteristics, respondents who reported having sex at least two to three times a month were 33 percent more likely to report a higher level of happiness than those who reported having no sex during the previous 12 months.
The happiness effect appears to rise with frequency. Compared to those who had no sex in the previous year, those reporting a once-weekly frequency were 44 percent more likely to report a higher level of happiness. Those reporting having sex two to three times a week are 55 percent more likely to report a higher level of happiness.
But while personal income can be inferred by a neighbor's flashy new car or home renovation, sex is a more cloistered activity. So how do, say, men or women in their 20s know how frequently their peers have sex?
Though sex is a private matter, the mass media and other sources of information provide clues. For instance, Wadsworth noted, Cosmopolitan, Glamour, Men's Health, Men's Journal
and The AARP Magazine
— with a combined circulation of 30 million—frequently report the results of their own or others' sex surveys.
Television and film depictions might also play a role, and, Wadsworth writes, "there is plenty of evidence that information concerning normative sexual behavior is learned through discussions within peer groups and friendship networks."
As a result of this knowledge, if members of a peer group are having sex two to three times a month but believe their peers are on a once-weekly schedule, their probability of reporting a higher level of happiness falls by about 14 percent, Wadsworth found.
Wadsworth is also a research associate at CU-Boulder's Institute of Behavioral Science and his research interests include the general study of happiness.
He noted that the data do not necessarily prove that social comparisons cause the effects he observed. However, "I can't think of a better explanation for why how much sex other people are having would influence a person's happiness," he said.
The way most people engage in social comparison can be problematic, he noted. "We're usually not looking down and therefore thinking of ourselves as better off, but we're usually looking up and therefore feeling insufficient and inadequate."
On the other hand, people are social creatures and any sense of self or identity is dependent on others. In his introductory sociology classes, Wadsworth asks students to write three adjectives, any adjectives, to describe themselves.
"And then I ask them, 'Do your adjectives have any meaning whatsoever if you're alone on a desert island, in the sense that there's no one to compare yourself to?' "
Regardless of the adjective — attractive, smart, funny, poor — "these things are meaningful only if there's some sense of what other people are like," he said. "As such, we can only be wealthy if others are poor, or sexually active if others are inactive."