The wedding may be the ending of some fairy tales, but it’ supposed to be the beginning of a long, happy life together. In a recent survey of 4,000 divorced adults between the ages of 18 and 60, that was one bit of information that came out. Since the 1970’s the percentage of Americans who got a divorce has been above 40 percent. But why?

In a recent survey of 4,000 divorced adults between the ages of 18 and 60, researchers at the Austin Institute for the Study of  Family and Culture on  the “Relationships in America” got data on why people ended their marriages.

When it comes to marriage, some things never change. Sexual infidelity is still the most common reason for divorce. Nearly 37 percent said that their own infidelity or their spouse’s caused the end of their marriage. Even though our sexual mores have changed in recent years, married couples still expect their partners to remain faithful—otherwise why get married?

Women are more likely to file for divorce, something that has been the case for a long time. One reason is because women have become more financially independent and don’t have to stay in an unhappy marriage for financial reasons. Women expect more from a relationship than just a person who brings home a paycheck. They put more effort into a relationship. They have higher expectations for their marriage than men do. Some of the reasons they cite for a divorce besides sexual infidelity are: Not meeting their emotional needs; spouse’s immaturity; emotional abuse; and physical abuse.

Although marriage is not happening as much in those in the middle and lower classes, marriage is still thriving among the wealthy and educated Americans.