Is it a fair fight? Keep your arguments clean for a good relationship

Sure, having the perfect personality match helps a relationship. So does the right age difference. But if you want to have a long-lasting, intimate partnership, you and your wife need to be able to "repair" after conflicts that inevitably come up.

"In every good relationship," says leading American psychologist and marriage therapist John Gottman, couples have "repairing skills, and they repair early". It's the number one commonality in successful relationships, he says.

Gottman's certainty comes from 42 years of studying relationships, both as a professor at the University of Washington and cofounder of the Gottman Institute with his wife Julie. Together, they've authored many books, demonstrating that human relationships behave in replicable, and scientifically verifiable ways.

Don't leave her in pain

To err is human, Gottman says, but to repair is divine. "The thing that all good marriages and love relationships have in common is that they communicate to their partner," he says. "We repair things. We don't leave one another in pain. We talk about it."

That's where gentleness comes in. "In good relationships, people are gentle with the way they come on about a conflict," Gottman says. "They don't bare their fangs and leap in; they're very considered."

For example, he says: "Instead of pointing their finger, they say, 'Hey babe, I need to talk about it.' In bad relationships, it's, 'You're defective, and you need therapy.'"

Be emotional, not intellectual

The most effective repairs rely on making emotional connections rather than scoring intellectual victories. An effective repair doesn't come from analysing a problem, Gottman says.

Instead of turning it into a debate, report how you feel. Gottman says a successful repair might be: "When you walked out of the room, that really hurt my feelings, because I felt like what I was saying was unimportant to you. I need you to stay in the room when we talk about an issue."

Be more Italian

The outlook is that some cultures see opposition as being disrespectful. But not every culture is like that. "In Italy," Gottman says, "if somebody tells you that you're full of s**t, you say, 'That's probably true, but so are you.'"

Instead of seeing conflict as a sign that you and your partner are incompatible, you can see it as a natural, constructive part of knowing somebody really well.