What is One of the Main Reasons Relationships Fail?

Last month, I interviewed neuroscientist and philosopher Dr. Berit Brogaard, who’s written four books (!). Here are some of the things we discussed:

What is the one of the main reasons why relationships don't last? Are people in arranged marriages better off? Will you ever biologically feel the high from the beginning of a relationship later on? If we're drawn to opposites, and that causes relationship issues, what is the best way to change ourselves? 

Take a look and let me know what you think!