All kinds of fairy tales end with a young couple in love and a line that goes, “And they lived happily ever after.” For the most part, research indicates that marriage does bring a lot of benefits.

However, psychologists say that researchers may not be taking in the whole picture. Marriage may make people “happily ever after” only if they’re already inclined to be happy in the first place — and nothing too serious comes along to disrupt the union.

Essentially, psychologists argue that much of the research touting the “benefits” of marriage (improved physical health, an enhanced social life and the likelihood of higher earnings, among other things) is flawed because it ignores the issue of “self-selection.”

For example, studies have shown that married people tend to be healthier than unmarried people. However, those studies aren’t accounting for the fact that people with a lot of health problems may be less likely to get married — and more likely to get divorced — than people with no health problems (or very few). People with chronic health conditions, on the other hand, are more likely to face spousal abandonment. That leaves a self-selected group of healthier-than-average married people to be studied.

Basically, psychologists are warning people not to get caught up in the “happily-ever after” myth just because they see a lot of facts and figures that seem to support the idea that happiness is mostly a couple’s prerogative. Falling into that trap could too easily encourage someone who is happy being single into getting married — or someone who is unhappily married into staying in a bad relationship.

If your marriage isn’t what you’d hoped it would be, and you don’t see a chance that it will improve, find out more about your options. A divorce isn’t the end of the world. In fact, it can be just the beginning.