Unbeknown to me, family lawyers apparently call January "divorce month". As the Christmas tree is thrown out and the wrapping paper cleared away, the empty champagne bottles taken out behind the garage, Google searches for terms such as "divorce lawyer" and "file for divorce" spike.

Many of the people researching how to untie the knot will probably not do so. But some will.

Mr Brad Wilcox and Mr Samuel Sturgeon of the Institute for Family Studies suggest that there might be good reason to hold off, particularly if you have kids.

Of course, there might be good reason not to hold off. But the majority of divorces involving kids don't come from "high-conflict" marriages or situations involving abuse.

Mr Wilcox and Mr Sturgeon point to data indicating that most divorces come from couples who are still basically functioning as parents.

Counter-intuitively, kids whose parents divorce amid flying crockery and lurid accusations may actually do better, post-divorce, than kids whose parents unhappily fizzle out.

But if you think about it for a while, that's not all that surprising. In homes with major conflict, divorce brings a certain measure of peace and stability. But if your parents are basically civil to each other, divorce could come as an unwelcome surprise.

Our parents, our family unit, are the first and most bedrock fact of our lives. Suddenly breaking that apart - for no reason apparent to the children involved - shakes a faith in the world that will never be rebuilt in quite the same way.

Moreover, divorce often means downward economic mobility. Unless you are hugely wealthy, splitting your income across two households means that sacrifices have to be made by both parties and, often, that financial stress is added to the emotional upheaval of unravelling two lives.

Small wonder, then, that the children of divorce tend to have worse outcomes on various measures than the children whose parents stay together.

According to Mr Wilcox and Mr Sturgeon, "divorce typically doubles or triples the odds that children will experience depression, delinquency, school failure or future relationship difficulties".

But children aren't the only reason to consider sticking it out. Divorce may be emotionally and financially traumatic for children, but it is also, of course, emotionally and financially traumatic for adults. And it's not clear that in the end, people who leave low-conflict marriages end up any happier than those who stick it out through a rough patch - even a years-long rough patch.

Some people consider divorce at one point, but don't go through with it. When they are asked about it later, most of them say they're glad they didn't do it.

One study compared people who divorced with those who didn't, finding that the people who didn't divorce ended up as happy as those who did. Sixty-four per cent of them even reported that they were happily married.

Of course, there's a risk that some of this finding is what social scientists call "selection effect". The people who considered divorce, but didn't do it, might not have been as unhappy as the people who took action.

It would be surprising if selection effects didn't account for at least some of these findings. It would be even more surprising if selection effects accounted for all of them.

We have a script in our heads about what divorce does, much of it lifted from the divorce revolution of the 1960s and 1970s. Two people meet... They fall in love... They develop irreconcilable differences, or they grow apart, and must split so that at least one of the parties can develop into his or her truest, highest self.

But more recent research suggests a very different truth about happiness. As psychologist Daniel Gilbert argues in the brilliant book, Stumbling On Happiness, unless our circumstances are truly unbearable, our brains will seek to find their natural level of happiness, like floodwater evening out across a plain.

Whatever we are stuck with... Whatever we commit to... We will find ways to make it work - and we will be just as happy with it as we would have been with any other outcome.

Under this theory, all other forces being equal, those who avoid divorce end up with the same long-term level of happiness that they would have had post-divorce. And they skip the short-term financial and emotional pains of separation.

So a lot of people who are thinking about observing National Divorce Month might be better off if they delayed the festivities for a while and started hunting for reasons to celebrate their marriage instead.

BLOOMBERG

•Megan McArdle is a Bloomberg View columnist and the author of The Up Side Of Down: Why Failing Well Is The Key To Success.