I do think that people are getting dumber. We have smart people making better technology so the majority of people don't have to think anymore. I think a perfect example of people getting dumber is hearing statistics that so many people are living paycheck to paycheck. This has been a topic before this recession ever started. If people have a ton of credit card debt and are not saving for their future and living beyond their means then I think that is all the proof we need. You wouldn't catch my parents or grandparents ignoring their financial well being. I am thankful I paid attention.
There was a time when every young person stayed in school and graduated. Then, society got really lax on moral values like you don't get pregnant while you are in high school, drop out of school and go on welfare to support the baby because the father is too young to support a family or doesn't want to. As a result we have a lot more uneducated people, and they are mostly people who are living on the edge of poverty. They aren't any dumber than previous generations, they just gave up on education. Education is not the answer to everything, but at least you know how to read, spell and use decent grammar. If you don't have those skills you might be just as smart as someone who can, but you don't appear to be.
No, there really isn't any difference in the proportion of smart to dumb people in the world than there was a hundred or a thousand years ago. We are simply more exposed to this broad range of people in more invasive ways due to the influence of media such as television and the internet, so it may seem as though people are dumber. Really, though, we're just the same as we've always been.
It must be relative values. I guess people might seem less intelligent because there are so few 'geniuses' per capita, but that hardly means the average person is less intelligent now compared to 20, 50, or even 100 years ago.
The only thing I think that a person could point to that shows greater intelligence in the past is great minds like Franklin or Descartes or other masters of many subjects. What people don't understand though is that these 'masters' of many subjects would be lost in an modern 200 level course in most of the subjects they were masters in. Descartes was just starting to grasp geometry, something that is now taught to 15 and 16 year olds.