This is pecking behavior. It's common in all highly stratified hierarchical social organizations. It is sexist, not because it's always been this way amongst both sexes, but because of the double standard of acceptability. Men are brutal toward each other, and more so toward women in the pecking, denigrating comments. It's just normalized and allowed for men. Expected even, boys will be boys. But when women do it.... Oh boy! She's the scum of the earth.