A correlation (nothing more apparently) has been found between watching TV and becoming a bully. The more a kid watches TV, the more likely he will turn into a bully. Same for the use of drugs - that finding goes way back.
We learned, through dealing with video-game induced tantrums with our autistic son, that the brain has a hormonal system (among others) that is termed "adrenergic," meaning it is tied in with an adrenalin-like neurotransmitter. He doesn't play video games any longer. The NT system in his brain that "doesn't work right" is the one that was affected by the Pitocin -- the oxytocic system. I think it is virtually an opposite of the adrenergic system, which may explain some of his problem with tantrumming (on overstimulation).