Human intelligent doesn't rally change at a fundamental level. People are no more or less stupid than they have ever been as individuals. Collectively, we tend to get smarter as we accumulate knowledge and experience.
Humans aren’t getting dumber. We’re more educated and more technologically advanced than we’ve been at any point in history.But one of the side effects of technology is that it exposes us to the stupidity that has been under the surface for so long. All the idiots we see on social media have been there in every generation, but until recently their idiotic opinions were kept to themselves. We’re more interconnected than ever before, but that also shows just how far we still have to go as a species.
I like to think of Human intelligence the same way i think of the American economy. the rich get richer the poor get poorer. the smart get smarter and the dumb get dumber. this is especially true when considering the IQ's of the majority of not just current adults but the ones being raised as well. this is because people with lower IQ's tend to have more children but teach their children less.
Our brains have always been wired this way.