Having children can ruin a marriage, experts say

Couples are at their happiest in the years soon after they wed and they eagerly anticipate the arrival of children.

But when romantic dinners and weekend breaks are replaced by sleepless nights and a shortage of cash the reality can be rather less appealing.

Daniel Gilbert, a psychology professor at Harvard University, said: "People are extremely happy before they have children and then their happiness goes down. It takes another big hit when kids reach adolescence.

"When does it come back to its original baseline? About the time the children grow up and go away."

Professor Gilbert added that many couples conceived believing children would bring them added happiness simply because they require financial and emotional investment.

He told the Happiness and its Causes conference in Sydney that research in the U.S. and Europe proved married couples were more content than singles. But those who were married were happiest when they were childless.

"Figures show that married people are in almost every way happier than unmarried people whether they are single, divorced or cohabiting," he said.

"Married people live longer, married people earn more money per capita, married people have more sex and enjoy it more. Children do seem to increase happiness while you're expecting them, but as soon as you have them trouble sets in."

However, Richard Tunney, assistant professor-of psychology at the University of Nottingham, said humans were designed to reproduce so being childless should not be the key to a happy partnership.

"From an evolutionary point of view we are programmed to procreate," he said. "It would not make sense for having children to make us unhappy.

"However, in countries like Britain having children is hard. Your finances are hit, childcare in this country is appalling and, for women especially, their careers suffer. That is not the fault of having children per se, but of society."

Studies in the Netherlands during the 1990s suggested married couples with two children were less happy than those with none.

Other research has shown that the period immediately after child birth can be the most fraught couples experience.