How to stay together

What best predicts whether a marriage will last?

The crucial predictors, say the researchers, are the presence of facial expressions that accompany emotions such as contempt. Gottman says that just watching a couple and looking for this expression, described as a sideways pull of a corner of the mouth accompanied by rolling eyes, is enough to make a good guess about a couple's suitability. "This is our best predictor," he says. "Contempt is the sulphuric acid of love."

We are told that the entire model has a 94 percent success rate in predicting divorce.

Here is some positive advice for Valentine's Day:

Gottman may also have stumbled across the secret of a lasting relationship - simply ignore the nasty comments from your partner. He says that courting couples tend to ignore negative statements and pay more attention to positive remarks. Once married, this trend often reverses, although couples that remain together into their sixties retain this outlook.

How about gay couples?

...gay and lesbian couples, as well as heterosexual couples that do not marry, hold on to the positive value of courtship better than straight partners who get hitched, he says.

For more information, read The Mathematics of Marriage: Dynamic Nonlinear Models. Are they joking with that title?