Why do girls stay in abusive relationships?

Good girls have been dating bad boys since at least the fifties. Image from flickr.com

Last week, the inspirational South African athlete Oscar Pistorious was charged with the murder of his girlfriend, Reeva Steenkamp. Following this, the mother of his ex-girlfriend, Samantha Taylor, posted these chilling words on Facebook:

“I am so glad that Sammy is safe and sound and out of the clutches of that man – there were a few occasions where things could have gone wrong with her and his gun during the time they dated. My condolences to the family whose daughter has passed away. My heart breaks for you.”

Now I cannot judge, to any extent, whether Pistorious is guilty or not. But this story does lead me to wonder about why girls date guys who they know are not in their best interests.