I spent the last decade surrounded predominantly by illiterate people. These comments are intriguing, but I don't think the effect is as strong as you make out. I never noticed any real difference in how illiterate people view the world, except that they are generally more prone to believing conspiracy theories.

If you can not read or write, then you do have to find other outlets for your energy. Music plays a bigger role in the lives of illiterates I found. I would say on the whole they would seem more extroverted and social, too.