Huh. I guess I came off as sounding kind of angry in my last post. Duke, I wasn't directing my comment at anyone in particular; mostly I was trying to counter the caricature of the researchers doing lame research. The study compared two random groups of people who each played a video game for something like 20 minutes, then they were tested on various things. The idea was to see what the immediate effect of having played was. An analogy with the blood pressure is helpful: the report isn't claiming that gamers in general have high blood pressure (in which case it would be appropriate to ask if there was some other factor, like gamers' typical diets, that was the real cause), but rather that immediately after playing a violent game your blood pressure is likely to be higher. Likewise, they aren't necessarily claiming that gamers are more permissive in their stance on drinking/smoking, but rather that immediately after playing a game like GTA, people were more likely to have permissive attitudes.
The assumption (especially in the news article) is that it's possible to play games enough that what initially is a temporary effect becomes a general part of your behavior.
And Smock, I agree that a control group who didn't play any games would've been a good idea, but in theory the group of people who played the Simpsons game were the controls for the GTA subjects.
