There are freakishly happy couples who never fight – and those who argue about everything from grocery bills to the colour of their dish towels.
And even if they make it to their 20th wedding anniversary, they're unlikely to change, new research suggests.
That's bad news for scrappy couples who think things will get better as their relationship skills improve.
"The most important takeaway is there is a lot of stability in conflict," Claire Kamp Dush, lead author of the study and an assistant professor of human development and family science at Ohio State University, told Time.
"If you're finding it difficult to live with the level of conflict in your relationship before you get married, you probably shouldn't get married."
The findings echo research by John Gottman, the Seattle-based psychologist famous for his 94-per-cent accuracy rate in determining whether newlyweds will divorce within six years. The predictions are based on the level of criticism, contempt, defensiveness and stonewalling (emotional withdrawal) in their marriages.
Ms. Kamp Dush's study of marital conflict used data from a telephone survey that interviewed the same people up to five times between 1980 to 2000.
Researchers divided the couples by conflict level: low (16 per cent), moderate (60 per cent) and high (22 per cent).
Using marriage types developed by psychologists, researchers identified "validator marriages" – those in which spouses shared decision-making and had moderate levels of conflict – as the healthiest, Science Daily reports.
But don't think you can create a "validator" relationship if you don't already have one.
"Before you get married," Ms. Kamp Dush said, "you need to think about the level of conflict you can tolerate."
So much for relationship books and couples therapy.
Do you believe high-conflict couples are doomed? Do you know any who have changed their ways?