Actually I would say "no". Each generation is more intelligent than the last. It's just that when people grow up they forget what it was like to be young and find themselves seeing things differantly. In general the older generations are always intimidated by the new ones. The "old fogeys" when you were young saw you the same way.
At any rate I think one of the problems with our society is the fact that our CULTURE has lost touch with the actual capabilities of children who are increasingly smart, and "maturing" mentally in a lot of areas (if not all) at an increasing rate. This attitude can be found in things like toys, where what people seem to think a 12 year old is able to figure out and find entertaining is often not the reality of the situation.
Not to long ago we had a situation I read about where a young kid got upset with a baby sitter, was able to remove a gun from where it was kept, load it, and then shoot the guy. I'm pro-gun, and don't see this as a gun control incident really, but rather a point that by common mentality the kid should never have had the intellectual capability to do all of that (the act itself being a lack of emotional maturity and understanding of what it is to kill someone).
To be honest, I think video games are rapidly replacing the toys of the past (if they haven't already) largely because the toys of yesteryear can't occupy the young minds of today.
Kids are quick to mark things as "doofy" that would have contented the young of earlier generations.
I also feel that this is why people are increasingly shocked by the crimes committed by children. It boggles the mind because at one time such things were simply not possible, but today they are, because children have changed, and society has not been able to adapt to those changes.
In my generation (I'm 34) I frequently felt that the system made the wrong assumptions about me and what I was capable of. I know other generations have felt the same way, and I think the problem is increasing as the capabilities of humanity increase.
I also justify my attitude by looking at the performance of athletes in years past, and how goys like Johhy Weissmueller (might have the name wrong, the dude who played Tarzan in movies) were considered almost "bionic" in how well they could swim, yet now their records are a joke. The most unbeatable seeming sports records are usually overcome by the next generation. Steroids only account for so much (especially seeing as old athletes were using them before the problems were uncovered).
If people's physical capabilities increase, and by all evidence I've seen they do, it's foolish to assume that mental abillities remain stagnant. While emotions are behind intellectual development I think even in terms of emotional maturity kids are progressing faster.
What seems like "Stupidity" might actually be caused by a mind working above the level society holds it to. Not always, but sometimes.... and honestly, young people still tend to have a lot of energy and do adventuresome things that ARE stupid to the older people. However this has always been the way of things.
Racing hot rods, "Rumbles" (to use an archaic term, they even wrote books about the big fights kids used to get into), and similar things have been going on forever. It's just that newer generations find newer stunts, and with the media the way it is, when something impressive (or more frequently: tragic) happens everyone hears about it, which was not the case for the majority of history. It might seem like kids are killing themselves being stupid in greater quantities from before, but such is not the case, it's about the same level as it's always been (allowing for our population) it's just now everyone hears about it and people think they can track the statistics where they couldn't before.