Australian study finds out what makes romance last

ADELAIDE, Australia – If you're looking for happily ever after, Australian researchers have a suggestion: Find a partner who shares your smoking habits.

Researchers at Australian National University studied 2,482 married or cohabiting heterosexual couples over a seven-year period to pinpoint what the relationships that were still going strong had over ones that fizzled.

So what predicts romantic longevity? Age, for one.

Couples in which the man was one year younger or up to three years older than the woman had less than half the separation risk of couples where the man was nine or more years older. Couples in which the man was two or more years younger than his partner also showed a higher risk of splitting up.

The study released this week – called "What's Love Got to Do With It?" – also found that relationships in which the man was at least 25 at the time the couple got together were more likely to last. So were ones where both partners shared a desire to have children – or shared a desire not to.

Money, too, plays a role: Couples with low household incomes were more likely to split than those with moderate or high incomes. Men who were unemployed had less stable relationships, as did men whose parents had separated.

A nicotine habit can have a profound impact. Relationships in which one partner smoked and the other didn't saw their risk of separation shoot to more than 75 percent of those in which neither partner smoked.

The study found, however, that religion, education levels, and alcohol consumption had no effect on marital stability.

The researchers used data from the "Household, Income and Labour Dynamics in Australia Survey," conducted by the government from 2001 to 2007. - AP