Brain size has roughly tripled in the last 4 million years of human evolution. If the within species correlation between intelligence and brain size is about 0.4, and evolution selected humans to be smart, not big brained per se, then as much as brain size has increased, it arguably increased no more than 40% as much as intelligence has increased because brain size was just a spandrel for intelligence. If a mere by-product of selection for intelligence tripled in size during the last 4 million years, imagine how extreme the direct selection for intelligence was!
So what is it about humans that is so many quantum leaps smarter than chimps? I would say, it’s our ability to ask questions. Chimps can be taught sign language and some can acquire large vocabularies and communicate effectively and be good conversationalists, but they never ever ask a single question. The ability to ask questions is a uniquely human ability. Even babies who speak only a single word can ask questions: “mamma?”
And it’s not because chimps lack curiosity or can’t learn the linguistic skills to ask questions…it’s because…I just figured out why!
In order to ask questions, you have to know that you don’t know. In other words you need meta-knowledge (knowledge about knowledge; knowing you don’t know) and true self-awareness. Self-awareness and the ability to acquire meta knowledge were quantum leaps forward in intelligence, likely associated with the tripling in brain size.
It also explains why talk show hosts are often brilliant. Their job requires them to ask questions:
Pumpkin Person 
Chimps can be taught sign language and some can acquire large vocabularies and communicate effectively and be good conversationalists, but they never ever ask a single question.
Seriously? I’ve heard of chimps learning several hundred symbols, but that doesn’t seem like a large vocabulary.
Nonetheless, I think you’re probably at least partly correct here. If you’ve ever read Godel, Escher, Bach, then you’d know that one key aspect of all intelligence is to be able to think recursively- or as you call it, meta-knowledge. I doubt lower apes have this much at all, even if they rotely memorize fairly large vocabularies.
Their vocabs are large compared to what a lot of people expected, but tiny compared to humans.
And you don’t have to call them lower apes. You can just call them apes as I explained here:
https://pumpkinperson.com/2014/10/10/apes-are-monkeys-and-humans-are-not-apes/
“It also explains why talk show hosts are often brilliant. Their job requires them to ask questions:”
😀
Sorry but it is too stupid so I dont know what to say. You should seriously edit the article and supress this sentence, I know that you are too smart to write this kind of silliness.
Oprah may be smarter than average, but the amount of BS on her show is astounding.
That’s true. I came up with some theories to try to explain that paradox:
https://brainsize.wordpress.com/2014/07/27/if-oprahs-so-smart-why-does-she-promote-irrational-ideas/
Oprah is brilliant? LOL
Please read this
its on artificial intelligence
http://waitbutwhy.com/2015/01/artificial-intelligence-revolution-2.html
heres an extract.
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ASI (Artificial Super Intelligence) would think much faster than any human could—but the true separator would be its advantage in intelligence quality, which is something completely different. What makes humans so much more intellectually capable than chimps isn’t a difference in thinking speed—it’s that human brains contain a number of sophisticated cognitive modules that enable things like complex linguistic representations or longterm planning or abstract reasoning, that chimps’ brains do not. Speeding up a chimp’s brain by thousands of times wouldn’t bring him to our level—even with a decade’s time, he wouldn’t be able to figure out how to use a set of custom tools to assemble an intricate model, something a human could knock out in a few hours. There are worlds of human cognitive function a chimp will simply never be capable of, no matter how much time he spends trying.
But it’s not just that a chimp can’t do what we do, it’s that his brain is unable to grasp that those worlds even exist—a chimp can become familiar with what a human is and what a skyscraper is, but he’ll never be able to understand that the skyscraper was built by humans. In his world, anything that huge is part of nature, period, and not only is it beyond him to build a skyscraper, it’s beyond him to realize that anyone can build a skyscraper. That’s the result of a small difference in intelligence quality.
And in the scheme of the intelligence range we’re talking about today, or even the much smaller range among biological creatures, the chimp-to-human quality intelligence gap is tiny.
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And like the chimp’s incapacity to ever absorb that skyscrapers can be built, we will never be able to even comprehend the things a machine an equal amount more intelligent than us, even if the machine tried to explain it to us—let alone do it ourselves. And that’s only two steps above us. A machine a bit higher than that would be to us as we are to ants—it could try for years to teach us the simplest inkling of what it knows and the endeavor would be hopeless.
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I enjoy the efforts you have put in this, thanks for all the great blog posts.