"Couples who cohabit before marriage (and especially before an engagement or an otherwise clear commitment) tend to be less satisfied with their marriages — and more likely to divorce — than couples who do not. These negative outcomes are called the cohabitation effect."
“I spent more time planning my wedding than I spent happily married,” .
"Women are more likely to view cohabitation as a step toward marriage, while men are more likely to see it as a way to test a relationship or postpone commitment, and this gender asymmetry is associated with negative interactions and lower levels of commitment even after the relationship progresses to marriage. "
Alhamdulillah for the wisdom of Islam. I included dating in the title because dating also has a poor record of avoiding divorces and are higher than correct Islamic marriages. Many people who dated for years, yet their marriages only last for a few months or a year, and the factors are similar as in cohabitation. For example this is because people say they date because "we want to know the person more", the same excuse used for cohabitation. Yet as the article and scientific study shows, knowing a person really well by being together so much doesn't decrease the chance of divorce.
The source of the study and article is: