From whence comes human intelligence?

[bjs1]

It is generally accepted that humans are the most intelligent creatures on earth. I am not disputing that claim. It seems to be supported by empirical evidence.

My question is, what makes humans smart? We do not have the largest brains; that honor goes to the sperm whale with a brain nearly 7 times the size of a human’s. We do not have the largest cerebral cortex; that is the elephant. We do not have the highest brain-to-body-mass ratio; that one goes to the ant.

What causes humans to (apparently) have the highest intelligence of any creature on earth?

[DrNoGods]

[Replying to bjs1 in post #1]

What causes humans to (apparently) have the highest intelligence of any creature on earth?

The "neocortex ratio" (ratio of neocortex volume to total brain volume) appears to be relevant as the neocortex is responsible for most of the higher cognitive functions in mammals (eg. abstract thought, and language capabilities, in humans). The neocortex is the newest part of brains to evolve and represents nearly 80% of the human brain (compared to half that in chimpanzees, for example). Encephalization quotient is a more general metric, but doesn't consider brain structure.

If you could resurrect a Homo sapien from 200,000 years ago they may have basically the same brain as a modern human, but their actual intelligence level would be far less because they did not have the benefit of 200,000+ years of accumulated knowledge that modern humans have. Their capacity for learning may have been the same though, and greatly exceeded their ancestors like Homo erectus.

[bjs1]

[Replying to bjs1 in post #1]

What causes humans to (apparently) have the highest intelligence of any creature on earth?

The "neocortex ratio" (ratio of neocortex volume to total brain volume) appears to be relevant as the neocortex is responsible for most of the higher cognitive functions in mammals (eg. abstract thought, and language capabilities, in humans). The neocortex is the newest part of brains to evolve and represents nearly 80% of the human brain (compared to half that in chimpanzees, for example). Encephalization quotient is a more general metric, but doesn't consider brain structure.

If you could resurrect a Homo sapien from 200,000 years ago they may have basically the same brain as a modern human, but their actual intelligence level would be far less because they did not have the benefit of 200,000+ years of accumulated knowledge that modern humans have. Their capacity for learning may have been the same though, and greatly exceeded their ancestors like Homo erectus.

Ok, but the horse has roughly the same neocortex ratio as humans and has been around as a social animal nearly 25 times as long as humans have. So if the neocortex ratio, along with social learning, was the primary cause of intelligence then shouldn't horse have outpaced humans, or at least be really close to us?

[DrNoGods]

[Replying to bjs1 in post #3]

Ok, but the horse has roughly the same neocortex ratio as humans and has been around as a social animal nearly 25 times as long as humans have. So if the neocortex ratio, along with social learning, was the primary cause of intelligence then shouldn't horse have outpaced humans, or at least be really close to us?

Where do you get that a horse has roughtly the same neocortex ratio as a human (not just cortex, but neocortex)? For encephalization quotient (EQ), humans are about 7.44 compared to horses at about 0.86 (one source), so a huge discrepancy there. But I couldn't easily find the actual neocortex ratio of horses compared to humans, other than some nontechnical articles saying it was "much smaller" in horses.

But there is also the fraction of a brain that is dedicated to certain functions. A dog, for example, has about 40x more "brain power" devoted to olfactory functions compared to a human (and the olfactory bulb of sharks occupies two-thirds of their brains), while humans have much more brain power devoted to the more complicated functions we carry out like social interactions, abstract thought, etc. So it isn't just one "thing" that makes humans more intelligent than other primates or other animals in general, but the combination of brain size, structure, and how the various brain sections are allocated to certain tasks and interact with the rest of the brain.

Despite our more advanced and capable brains, we've yet to figure out all the details of how brains work, especially ours. But intelligence was evidently a tremendous evolutionary advantage and from Homo habilis to Homo sapien, brains progressively got larger and more capable due to the advantage higher intelligence afforded.

[Gracchus]

[Replying to DrNoGods in post #4]
Better question: Where did it go? Or was it just imagination?

[Clownboat]

[Replying to DrNoGods in post #4]
Better question: Where did it go? Or was it just imagination?

Where did what go?
Was what just imagination?

Curious minds want to know...

[Gracchus]

[Replying to Clownboat in post #6]
Whither went human intelligence? Religions, national borders, the human world seemingly endlessly divided into "us's" and "thems" do not indicate intelligence to me. We all want to think we are intelligent, but it is probably just a fairy's tail.

[Clownboat]

Whither went human intelligence?

I'm confused because humans are intelligent. The most intelligent animal on the planet in fact.

Religions, national borders, the human world seemingly endlessly divided into "us's" and "thems" do not indicate intelligence to me.

Now I think I get it. Your confused about human intelligence because you think intelligence has something to do with 'us' vs 'them' behavior.
'Us' vs 'Them' is cult behavior and helps groups unite against a common cause or enemy. Nothing to do with intelligence.

We all want to think we are intelligent, but it is probably just a fairy's tail.

It is not a fairy tale that humans are the most intelligent animal on the planet.

"Humans have been widely acknowledged as the most intelligent species on the planet, with big brains with ample cognitive abilities and processing power which outcompete all other species. In fact, humans have shown an enormous increase in brain size and intelligence over millions of years of evolution."

[Gracchus]

[Replying to Clownboat in post #8]The proof is in the pudding. Humans are the biggest enemies of species Homo. They are driving themselves towards extinction. It is hard for me to see this as intelligent behavior. That comedian was wrong. Death will cure stupidity.

[Clownboat]

The proof is in the pudding.

Then don't ignore the pudding.
Copy/paste to save time: "Humans have been widely acknowledged as the most intelligent species on the planet, with big brains with ample cognitive abilities and processing power which outcompete all other species. In fact, humans have shown an enormous increase in brain size and intelligence over millions of years of evolution."

Humans are the biggest enemies of species Homo.

Can you explain what this means?

They are driving themselves towards extinction. It is hard for me to see this as intelligent behavior.

I would argue that you (all of us) have made poor decisions at some point in your life. This does not make you unintelligent, it makes you an intelligent being that made a poor decision.

To recap, your initial question was: "Whither went human intelligence?"
The answer is that it hasn't gone anywhere. Humans are still intelligent. The most on the planet in fact.