"I found a study which shows that social networking sites are making people dumb?"
Now this is an example of a very broad question not backed up with any supporting data, that in itself is based on an opinion.
However, look at it this way. Someone just today told me..."I don't want to PLAY the games. I want to MAKE the games. (And the money.)
I agree with that last paragraph. I stopped using the net for just fun about a year after I got online. If I were a gozillionaire, I'd still feel guilty just doing fun stuff on the net. Too much to see, do, and learn.