How much sex is enough? You might question the premise of that query, but new research reports that there's a limit to the benefits of carnal pleasures. Beyond a certain frequency, more sex does not mean more happiness. One possible reason: as long as we are doing it as often as our neighbors are, we're content.

For a recent paper in Social Psychological and Personality Science, Amy Muise, Ulrich Schimmack and Emily Impett, all at the University of Toronto Mississauga, analyzed three survey samples comprising more than 30,000 Americans. They found that among couples, sex frequency positively correlated with satisfaction in life, confirming earlier reports. (They found no such link for singles.) The difference in happiness between those who had sex less than once a month and those who had sex once a week was at least as great as that between those earning less than $15,000 a year and those earning more than $100,000. Direction of causality is unclear; their analysis suggested that sex frequency increases relationship satisfaction, which increases happiness, but they also found evidence for the reverse pathway, in which general life satisfaction increases relationship satisfaction, which in turn increases sex frequency.

Unlike in previous studies, a subtler pattern also appeared: at frequencies greater than once a week, the happiness graph flattened out. The reason “is an open question that we are exploring,” Muise says. Her team thinks one possibility is that people are satisfied when they are doing it as much as they think they should be, a standard set by their peers. Indeed, the average for couples is once a week.

In support of this idea, Tim Wadsworth, a sociologist at the University of Colorado Boulder, reported in 2014 in Social Indicators Research that happiness is positively correlated with sex frequency but negatively correlated with the sex frequency of others in the same demographic group, a rate people probably surmise from conversation and media. “How much sex is appropriate, like so many other questions, depends on what we think is ‘normal,’” Wadsworth says. One sees the same trend with income: a 2010 paper in Psychological Science reported that income rank among peers predicted happiness better than did absolute income.

So if you are worried you and your sweetheart are failing to keep up with the Joneses, there is an easy solution: just tell yourself you're having better sex than all those once-a-weekers.