Yes, team sports do socialize children. (My post was muddled, sorry) This may be a large factor in these children’s lives.
Children who watch films and play violent video games lose playtime—lose social time . There is nothing like getting out and playing with others. l have noticed since l was a child that after school playing has changed—and videos fill the void. That is certainly one thing that happens to children who must go in doors and wait until an adult returns from work. Social isolation is a factor in these killers.
Isolation with only yourself and a controller in your hand.
edit: just found this short article.
http://www.thedoctorwillseeyounow.com/content/kids/art3099.html