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The Beatles may believe that all you need is love, but according to a Cornell University scientist, a happy marriage requires a bit more—it requires an honest conversation about money.

Any Southerner knows that it’s only polite to avoid talking about politics, religion, or money at the dinner table. However, a new study from the Ivy League institution reports that if you want a happy and long-lasting marriage, it may be time to start talking about that tacky topic.

The study, published in the scientific journal Demography, says that couples who earn similar amounts of money are more likely to choose to start a life together. While we’re not suggesting you put your salary on your online dating profile, once you get to know someone, it may be worth opening up about your income. It’s an important conversation, because the Cornell researchers also found that when both people in the relationship earn similar amounts of money, they’re more likely to stay together, too. That’s right: Couples with similar salaries had much lower divorce rates.

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To reach this conclusion, the Cornell researchers studied the Census Bureau’s “Survey of Income and Program Participation” from 1996 to 2013. They wanted to know how money and work affected whether couples who lived together would marry or separate. While the traditional thinking is that if the man in the relationship is a good provider, it’s a sign of a potentially long lasting relationship. Don’t tell your nana, but it turns out that tradition is wrong, at least on this occasion. They found that couples who made the same amount of money stayed together far longer than couples where one person made significantly more than the other. Or in science-speak, “within-couple earnings equality promotes stability” andcouples with higher and more equal earnings are significantly less likely to separate.” 

That realization may take time to sink into the minds of men and women, though. A recent survey of nearly 5,000 adults by the Pew Research Center found that more than 70% of Americans say it is very important for a man to be able to support a family financially, but less than one-third say the same for a woman. Guess your nana has a while to stick with tradition, while you start having honest conversations about money.