Evolution in action ?!

Yeah, this seems to not be actual research. First off to the best of our ability to measure intelligence, we've been getting smarter. Second mutations don't always make people stupid. Indeed, mutations are responsible for our brainpower. All of it.

also autism...

Actually a couple of thought, I am too late in to actually theorize with any point you guys made up above me so allow me.

First, I'd like to believe I am adequately intelligent. I only have a GED, but I read a lot, I like practicing new languages, I participate in many rather creative activities and many other things. For the most part I'd be considered stupid by these studies due to my grades (Mostly due to my laziness or general dislike for schoolastic activities) and my General Education Diploma. I am now apprenticed as a carpenter, which further decreases my standing in these studies, or so I would assume (Carpenter does not equal Sir Doctor Professor van Thom). So I personally find these studies less than optimal to make "Factual" claims or present solid evidence. Yes, when we look at the people on the street we all think "Man, how dumb can you be?!?". But what is stupid? What is intelligent? And what about all those tribes people still living the traditional way in south america, in australia, in new zealand? Are they stupid because they have no degree or diploma? In the past there were many Native Americans that have gained diplomas on "Civilized Americans Schools", while still living close to their tribe after all. Another point that these studies aren't optimal is that they don't involve a necessary amount of people. They mostly are very localized, instead I would like to see one being cross referenced to MANY different countries, gathering from any major city, asking a good portion of the population. I know that this will probably never happen, but if it did I could give it a lot more trust than the studies I have read so far.

Actually the studies tend to be based on 'standardized' testing rather than grades or achievement, however even that is very culturally dependent- for example as a carpenter you tend to work outdoors and therefore process optical illusions involving intersecting lines differently than people acclimated to working in an office. People in regions where architecture is significantly less cube centered process these images even more differently. If people from a more primitive culture are given IQ tests where the traditional geometric shapes are replaced with varying animal tracks for pattern recognition their measured IQ shoots up about 40 points.

Yeah, IQ testing is extremely flawed. When it comes down to it, we don't even know how to define "intelligence" properly, much less measure it (we're getting closer, I think, but definitely not there yet), so anyone claiming that humans beings are "smarter" or "dumber" than they used to be is blowing smoke out their butt.