Love was designed by evolution to compel us to engage in behavior that will spread our genes into the next generation. But divorce, far from a modern phenomenon, has also been a part of human society from the very beginning.

Question: What does evolutionary psychology say about love? 

Satoshi Kanazawa: Love and all the other emotions are designed by evolution to compel us or incline us to engage in the right behavior, the correct behavior that would lead to reproductive success in the context of the evolutionary environment, so we are designed to love certain people that would be good for us reproductively. We are designed to find people attractive and we love people who would make great mates, who would make great parents, so that would be different for men and women, but we can predict whom men and women might fall in love with and love makes us do things that would ultimately be good, not necessarily for us, but for our genes, for the spread of our genes in the next generation 

Question: Why is the divorce rate so high? 

Satoshi Kanazawa: Well divorce probably has been part of human society for as long as we lived. Divorce, dissolution of marriage, dissolution of pair bonds exists in all known cultures in all known societies, so for whatever reason men and women who have bonded to produce children sometimes have split up, but most of the time the divorce was caused by the failure to reproduce. When either the man or the women is infertile and they couldn’t produce children that often led to divorce. That often led to dissolution of marriage or pair bonds, but another reason; probably the major reason why divorce rate is so high in western industrial socially imposed monogamous society is that because we don’t allow polygyny. One again, as I said before humans are naturally polygamist, successful men have always acquired multiple mates, but we don’t allow that in our society, so successful men are forced to divorce their previous wives who may have been passed their reproductive age in order to marry younger wives. If we allow polygyny, if you allow some men to acquire multiple mates divorce rate would go down dramatically because men don’t have to divorce their older wives to acquire new wives.