Jealousy is a possibility. I know that both guys and girls display it. I remember being a freshman in high school, and some classmates of mine targeted a good looking shy boy, to name call and physically assault, just like a wild pack of wolfs. What the boys had done was all out of jealousy. The boy who was bullied was very good looking and sang leads all the time in the chorus because his voice was incredible!
Also meaness, if it is just meaness that does not mean you ugly either