Actually there is a test that monitors just this, I'm not going to go into exactly how that works but you might be surprised to learn that people are on average 10 points higher IQ than they were in the previous generation and this seems to be the case as each new generation appears. There has always been the case that the older generation looks down upon the generation behind them and considers them to be less intelligent but with the advent of computers, laptops, tablets etc particularly in the area of abstract thought the younger generation has it over the older i am afraid. Think about it, we never had the internet in the 50's people had to make time to read when these days people are constantly reading, on their phones, online wherever they are and that means they are constantly learning, even if it is sometimes rubbish they are reading about it is still, none the less, mentally stimulating. Like i said it's easy to fall into the habit of assuming the younger generation are stupider but i think, from the information that i have read, that this simply isn't true. Of course there is a whole other argument about how to accurately measure IQ but that's another story
Stupidity is raising as time progresses while people are smarter but not more wise.