Yes. For me, every step away from the problems of modern society to a paleo or traditional approach yields a significant increase in my mental strength and endurance. You're not simply born with a level of intelligence; you can change it.
Holy shit, I still remember the mental fog that lifted back many years ago when I stopped eating junk food once and for all. My intelligence sky-rocketed around that time. It's hard to believe that so many people live in that fog, but then again I guess all around me I see the horrible effects of that fuzzy thinking.
It's a tough problem because in general, it's one's mental ability that must save one's mental ability. That's why for most people, I refer to eating junk food as being "in the hole". It's a vicious circle. Get dumber, eat more shit. And eat more shit, get dumber. The one enforces the other. Or more charitably, fall deeper into that mental fog, make worse lifestyle decisions, and make more lifestyle decisions, fall deeper into that mental fog.
I escaped from the hole many years ago, and it was a harrowing journey. It still is in some ways. I just feel sorry for the people who are still trapped in the hole. Years of my life have been consumed with trying to climb out, and often it wasn't very fun. It was extremely difficult and at times almost destroyed me. I'm glad I'm out at this point, and in the future, I would like to be of some help to other people like my past self of many years ago. If I had somebody who had already escaped to help me, it would have been so much easier.
Am I getting off-topic? I don't think so. Or maybe I am. Either way, yes yes YES. Eating paleo or whatever influences how I think. I have seen changes in my thinking processes. The change was for the better. Ridiculously better in fact. An epic change. But maybe what I was saying about the vicious circle and stuff was a tangent. Either way, it was an important tangent. Perhaps it will add something to the discussion of how paleo affects thinking.
Sometimes I wonder whether the average intelligence of people back 100 years ago was more than it is today. I can't imagine that it wasn't. Looking around at the people of today, holy shit it's embarrassing. And the junk food seems to be a significant culprit. Maybe 100 years ago it was more common to believe in something crazy and unscientific, but that seems more related to the knowledge base than the raw intelligence of the population. But perhaps there's been a net increase when it comes to knowledge and applying that knowledge? Yeah, I guess it would be pretty crazy to doubt that.
I'm in a virtuous circle right now. My lifestyle improves, my mental ability increases. And my mental ability increases, my lifestyle improves. I'm out of the hole, and I don't expect to ever fall back in. I eat absolutely no junk food ever, and I don't anticipate that to change ever. And a lot of other stuff. A good lifestyle isn't just eating clean. It's also recognizing how crazy everything else is too. Shampoo, running shoes, etc. All ridiculous. All destructive. At least for most people's utility functions, that is.
Perhaps there's a revolution going on. I hope so. We need to help civilization get out of the vicious circle and into the virtuous one before it's simply too late.