Why do why fall for emotionally unavailable partners?

In todays episode we talk about emotionally unavailable partners, and why we fall for them.  When we say emotionally unavailable we are talking people who keep their feelings and love at a distance.  Alot of times with these individuals they have no problem with surface level bonding, essentially you can have my body but I will disappear if you demand my heart.  Why do some of us keep attracting these types? And what can we do to course correct?