Depends on the person IMO. I do not believe video games can DIRECTLY cause violent behavior; though it can definitely contribute. It's like when you get into a fight because of someone teasing you; it is not directly their fault, but it definitely contributes to the fight.

I'm not saying violent video games are ALWAYS bad though. It really depends on the person's reactions to things. I've actually heard some people say violent video games are a good way for them to let anger out, so in these cases, they could be good.

So I'm not really leaning toward either answer, since it could be different for every person.