Daniel L. Carlson is an assistant professor in the Department of Family and Consumer Studies at the University of Utah and a senior research associate with the Council of Contemporary Families. Amanda Jayne Miller is an associate professor in the Department of Sociology at the University of Indianapolis. The views expressed in this commentary are solely those of the authors.

(CNN) Of all the things contemporary adults believe are vital for a good marriage, a satisfying sex life and fidelity are often the top two. So it's no wonder that a recent study that reports that American couples in the early 2010s have sex, on average, nine fewer times per year than couples in the 1990s did has set off alarm bells . The decline occurred only among cohabiting or married individuals rather than their single or dating counterparts.

This finding unleashed a wave of dire predictions about the future of happy marriages and a cascade of questions about how partners can make sure they are having enough sex. After all, according to Michele Weiner-Davis, author of "The Sex-Starved Marriage," infrequent sex threatens intimacy and ultimately the relationship itself. "Couples stop sitting next to each other on the couch. They stop laughing at each other's jokes. They don't spend time together. They stop being friends." she said in a 2014 talk at TEDxCU. To save marriages, Weiner-Davis urges the partner with the least interest in sex to adopt the Nike philosophy and "Just Do It."

We beg to differ. Here's what we've learned: the less couples worry about how frequently they have sex, the more they may be able to improve the factors that predict the greatest sexual satisfaction and highest quality relationships: communication, perceived fairness, and a sense of teamwork in the daily working of the household.

Don't get us wrong: We're big fans of happy, active, intimate, sexual relationships. But a lot of the worry about sexual frequency reflects some serious misconceptions about what researchers know and persistent myths about couples' sex lives.

Myth #1: Sex is on the decline for all couples (hint: share the chores and you might share a lot more)

The first misconception about couples' sex lives is that the average decline represents the experience of all couples. But in a study we conducted with our colleagues Sharon Sassler and Sarah Hanson, we discovered one important exception: among the 1,780 low- to moderate-income couples in our samples who were married or cohabiting between 1992 and 2006, parents who share housework are, on average, having sex more frequently than a quarter of a century ago. Egalitarian couples also report higher levels of sexual and marital satisfaction than couples who divide the work less equally.

Granted, only 30% of the couples we studied had adopted such egalitarian arrangements as of 2006. But that's a big increase compared to the past. Encouraging more such sharing might do more to increase sexual frequency and marital happiness than pointing couples to all those websites and magazine articles promising other ways to make your partner pant with desire.

Myth #2: Couples are having less sex because they are working too hard

Many people believe couples are too tired for sex because they are working too much. In fact, busy couples generally have more sex, not less. Looking at data from the late 1980s and early 1990s, researchers found that the busiest husbands and wives -- those who spent more time on housework and paid work -- reported having the most sex. We find something similar in our more contemporary data. Increases in the total time couples devote to unpaid housework results in significant increases in sexual frequency. While it is not entirely clear why more work equals more sex, it's possible that "work hard/play hard" couples carry the intensity and energy with which they pursue work into their time in the bedroom.

Myth #3: Couples need to have lots of sex in order to be happy together

It is true that, on average, couples who have sex at least once a week report themselves happiest in their relationships. But having sex more than once a week yields no comparable increase in relationship satisfaction. We have found that the association between sexual satisfaction and relationship satisfaction is three times stronger than the association between sexual frequency and relationship satisfaction. In short, more often doesn't mean better.

When it comes to couples' sex lives, quality trumps quantity, and sexual frequency is a poor predictor of sexual satisfaction. What matters is not how often couples engage in sex but how satisfied they are with their sexual encounters when they do have them.

Myth #4: More sex means couples are happy with their sex lives

The weak link between sexual quality and quantity highlights something very important. Just because a couple is sexually active doesn't mean the sex is satisfying. Indeed, a simple count of sexual frequency tells us little about how often couples prefer to have sex or if the sex is good for both partners.

Although sex is a way of demonstrating love and affection, it can also be a way of expressing traditional heterosexual notions of masculine domination and feminine compliance, with men deciding when, what, and how sexual acts are performed and the woman expected to satisfy what marriage counselors long considered to be his greater physical need.

Adherence to gender conventions may create frequent but unsatisfying sex when it makes husbands feel compelled to push for sex and wives to perform it as a "duty" -- just one more chore to be added to an ever-growing list. Historian Stephanie Coontz has conducted interviews with women who married in the 1950s and early 1960s, and she told us in an e-mail that many reported being told by premarital counselors that it was unfair to deny their husbands "relief" just because they were "not in the mood," and that a "normal" woman could always attain a vaginal orgasm. As one woman described the messages she received, "you should never show any sexual desire before marriage or lack of desire afterwards."

Even today, we found in research conducted with Brian Soller at the University of New Mexico, that although conventional gender attitudes lead to more sex by increasing male sexual control, they also negatively affect men's and women's abilities to take physical and psychological pleasure from sexual experiences. The same egalitarian attitudes that lead to shared housework may also deepen partner communication, which in turn leads to a greater sense of sexual intimacy.

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With all these myths out there, what should we do about them?

We need to close the self-help books urging us to "just do it;" sexual frequency isn't the magic elixir that will save marriages..

Rather than adding to couples' anxieties by urging them to work harder on their sex lives, let's talk more about how to help couples create partnerships based on mutual fulfillment and collaboration. Once couples engage in more equitable behaviors in the kitchen and living room, more pleasurable embraces in the bedroom may well follow.