Those couples that still have sex every night, despite all of life's other stressors, time commitments and distractions?
They're no happier than couples that have sex at least once a week, according to new research.
"Although more frequent sex is associated with greater happiness, this link was no longer significant at a frequency of more than once a week," lead researcher Amy Muise said in a release. "Our findings suggest that it's important to maintain an intimate connection with your partner, but you don't need to have sex everyday as long as you're maintaining that connection."
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It's like the study several years back that found that money can indeed buy happiness – but only up to $75,000 per year. As income drops below that point, so does happiness. As income increases over that number, however, levels of day-to-day happiness remain steady.
The same algorithm applies to sex: increase it up to once a week, couples get happier. Do the deed more than that and happiness idles.
The findings also transcended gender, age and relationship length - despite myths that sex is more important to men, and less important to both genders with age and years in a relationship.
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"Our findings were consistent for men and women, younger and older people, and couples who had been married for a few years or decades," Muise added.
Some caveats apply, however. The research only looked at couples, not singles. Indeed, the data didn't find any connection between frequency of sex and quality of life for unpartnered folks.
It also couldn't prove cause and effect, so experts don't know if happier couples tend to have more sex (up to once a week) or if having sex once a week makes couples happier.
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But concerned couples must be careful about how they hit the once-a-week minimum (if they're not currently there). Previous research has shown that couples who were told to double the amount of sex they were having actually had decreases in happiness.
The trick might be in finding a way to have more sex without it feeling like an obligation.
Once it becomes a chore, like everything else in life, it sucks out all the joy - whether you're doing it once a week or not.