Answer:
The answer to your question is different depending on who you're asking about. But for society as a whole, if people are raised knowing violence is wrong, and that TV violence is just on TV and not real, then there shouldn't be any bad effects. However, it's when people are raised not knowing these things that it can be harmful. Like, in Tom and Jerry for instance, after the characters have been attacked and chopped in half or whatever, they always get up, ready for another torturing, or another episode. Some people think that in real life that's what happens, they always get back up and are never killed, and so they experiment in torturing real people. Sometimes they also think violence is right as that's what happens on TV- something that's worshipped in today's society. If they see their favourite movie stars and idols doing it it must be cool, fun and the thing to do. That's the sort of thing that leads to problems.