There is definitely a reason for why she is the way she is there are many possibilities though her child hood is probably the most likely reason. We got the impression from Sirius that being a Black child wasn’t all it was cracked up to be. I’ve always believed that she learned her favourite form of punishment through firsthand experience. She was brought up to be the way she is, and in some twisted way maybe Voldemort was the first person to give her the attention she always craved.