You know how stupid the average person is? Well, by definition half of them are dumber than that.
Truth is a person with an average, or even slightly below average IQ is fairly bright… Assuming they bother to use the brains God gave them. But still 25%+ is just too dimwitted to ever amount to much mentally, no matter how hard they try.
Then there are a whole lot of people who don’t try. They are too busy watching reality TV, getting high, getting drunk, or just being a pure dumbass to ever develop mentally.
And you have plenty of bright people who suffer from “Bullshit in, Bullshit out” syndrome. They may be fairly bright but their mind isn’t working right because of all the crap they’ve put into it. Most Liberals fall into this group.
To top it all off, no one cruises around all day at full mental power all the time. We get tired and we get distracted. So, even other wise bright people often are walking around using less mental power than a typical ape.