# The limits of human intelligence (or, why elves are evolutionarily implausible)



## Jabrosky (Jun 14, 2012)

The Limits of Intelligence (pdf)

This article argues that since anatomically modern human (_Homo sapiens sapiens_) brains cost an extremely high amount of energy to maintain, we as a species may have reached close to the pinnacle of our cognitive evolution. In other words, we're probably as smart as we'll ever be; we can't evolve significantly greater intelligence. This made me wonder about all the elves, aliens, and other fictional races in speculative fiction that are purported to be smarter than humans. If these races are the product of evolution by natural selection like ourselves, they may not be evolutionarily realistic. Of course this won't deter fantasy worldbuilders who eschew science altogether, but I think this is worth considering for those of us who prefer some degree of biological realism in our fantasy.

Your thoughts on this?


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## Mindfire (Jun 14, 2012)

I think it is possible to be "biologically realistic" and still have beings smarter than humans. It just requires you to allow for an origin of life that doesn't rely completely on evolution by natural selection.


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## Queshire (Jun 14, 2012)

Well, I'd say don't take that information to mean you CAN'T do something, take it as a challenge to figure out a way you CAN do it.

For instance, the problem's the energy they need right? Well, what if instead of getting energy just from their food they also get energy from sunlight? The sun is the next best thing to infinite energy, we simply can't harness it properly. Oh, and there's always the telepathic hivemind, or if you don't like that, maybe some telepathic version of the internet, where if you want to know something you can just look it up and then forget it when you don't need it.


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## Philip Overby (Jun 14, 2012)

I like thought-provoking articles like this, but elves will continue to be in fantasy regardless of whether it's possible for them to exist or not.  A giant flying lizard that breathes fire can't really evolve to be able to speak multiple languages, but those exist in fantasy also.


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## Black Dragon (Jun 14, 2012)

Phil the Drill said:
			
		

> A giant flying lizard that breathes fire can't really evolve to be able to speak multiple languages...



What are you taking about?!  I'm fluent in six languages, counting three varieties of Elvish and an obscure Dwarvish dialect.


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## Queshire (Jun 14, 2012)

There was a show on discovery YEARS back where they theorized what dragons might be like if they really existed, though they didn't speak.


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## T.Allen.Smith (Jun 14, 2012)

I don't see how limits are relevant to fantasy or scifi. You want to be plausible but believable is another matter entirely.

People should be reading what you write to experience something other than what we know.


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## ThinkerX (Jun 15, 2012)

I tend to see elves as 'more other worldly' rather than 'more intelligent'.

There is also the bit about humans not making full use of their brains, either.


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## Feo Takahari (Jun 15, 2012)

ThinkerX said:


> There is also the bit about humans not making full use of their brains, either.



Ahem.

On-topic, I can easily see elves as the product of eugenics, targeted towards improving intelligence, and letting some physical weaknesses creep through (particularly if inbreeding is involved.)


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## Benjamin Clayborne (Jun 15, 2012)

I would argue that whether or not the laws of physics allows brains to get any more powerful, individual humans don't need the capacity for more intelligence. We're already Turing-complete.


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## Chilari (Jun 15, 2012)

Feo Takahari said:


> Ahem.



NOOOO! I just clicked on that and it didn't get blocked and I'm at work. Productivity's bane, and I can access it from work. This is not a good sign.

I would certainly like to see stories where the non-Earth critters are biologically and evolutionally plausible, rather than always magic when non-earth, like unicorns or dragons. Can't there be a non-Earth-real, non-magic fantasy being please? Fantasy games like Skyrim have done this (eg the Horkers), but you don't often see it in novels.


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## Steerpike (Jun 15, 2012)

I don't think the article should be viewed as limiting. It is interesting material, but only as relevant to a fantasy world as the fantasy author wishes to make it. There is no reason a fantasy race has to be constrained by this. Even if you adopt the view that the various races evolved, there is no reason you can't simply suppose that their brain structures are very different from those of real humans, and therefore function differently and are not subject to the limitations of human physiology.

Apart from that, many fantasy books with elves and other races presume that the races were in fact created by gods who really do exist in those worlds, and once you have creation by the active hand of a deity, the limitations of evolutionary biology can be thrown out the window.


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## ThinkerX (Jun 15, 2012)

> Ahem.



Doesn't really account for prodigies - or for normal people training themselves to memorize impossibly long numbers, perform very difficult calculations in their head, ect.  Perhaps a different definition of 'use'.



> On-topic, I can easily see elves as the product of eugenics, targeted towards improving intelligence, and letting some physical weaknesses creep through (particularly if inbreeding is involved.)



Kinda sorta like the elves in my worlds, except it was Lovecraftian type aliens doing the eugenic engineering, for utterly alien reasons of their own.


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## Alex97 (Jun 16, 2012)

You could just say that these more intelligent beings are more efficient in their use of energy than humans and can therefore be more intelligent.  Or as allready pointed out they can gain energy from more sources.  There's quite a few way round it and this sort of thing should limit what you can write but if you find a solution I soppose a fantasy/sci fi world will be more credible.


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## Saigonnus (Jun 16, 2012)

In reality, we are potentially as smart and innovative as we'll ever need to be as a species. We have the intelligence capability of contemplating the vastness of the universe, traveling therein and forming new complex thoughts and ideas. The only thing that that has really changed in the long term is what we know and how much we know as a part of our daily life. I would think, if you put a medieval chemist or significantly intelligent person like Leonardo Davinci into modern times, given enough time to adapt to the societal structures, he'll know just as much as us with what brains he had then. I have heard that human use 10% of their brains for everything we do, and it's only a matter of time before we manage to discover a way to tap into some of that "unused" space.

I think Elves and humans the same age are pretty equivalent when it comes to base intelligence and the only difference would be what they know from day-to-day within their society and the fact that they live longer so can acquire more information, have more experiences etc... in that time. 

That was always the difference I noticed in fantasy novels or role-playing. Humans are more rash and impulsive; driven to accomplish things now, since they may not live long enough to see their concepts reach fruition. Elves can afford in years to be more patient in their pursuits, so tend to be more relaxed in terms of accomplishing things. They can certainly be precipitous emotionally or arrogant like a human, but I don't believe they are any "smarter" than humans.

Any race of "smarter" creatures may not necessarily be smarter, or use their energy more efficiently. They may simply have followed a different technological/socialogical path than us and have a deeper understanding of things that are beyond us at the time. Whose to say if we captured their technology, we wouldn't be able to do the same things once we know how it works. This has always been prevalent in human behavior throughout the millenia, if someone seems to have the right idea on doing something, steal it and use it for yourself. 

A fine example of this is the spartans; which I equate as the nuclear weapons of the day, deterrant more than weapon since they didn't need to fight just from reputation alone and it took a lifetime to train the elite troops so were horrendously expensive in comparison with other warriors. Neighboring tribes that faced them realized that they could train in a similar fashion and reach perhaps 60% of the efficiency of the Spartan soldiers but with 10 times their number in only five years or ten... when the idea spread to other neighboring tribes, the Spartans became obsolete and everyone started taking chunks from their empire.


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## Ireth (Jun 16, 2012)

I'm of the opinion that the "we only use 10% of our brains" idea is a myth. Maybe we only use only 10% *at a time*, but we have lot of different areas in the brain that have different functions. You can't just say 90% of our grey matter is totally useless.


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## Reaver (Jun 16, 2012)

Benjamin Clayborne said:


> I would argue that whether or not the laws of physics allows brains to get any more powerful, individual humans don't need the capacity for more intelligence. We're already Turing-complete.



AHEM...Once again: *SAYS THE ANDROID WITH A SUPERCOMPUTER FOR A BRAIN.*


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## Benjamin Clayborne (Jun 16, 2012)

Reaver said:


> AHEM...Once again: *SAYS THE ANDROID WITH A SUPERCOMPUTER FOR A BRAIN.*



Hey, I could have a 1985 Casio for a brain and it would _still_ be Turing-complete.


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## Reaver (Jun 16, 2012)

Benjamin Clayborne said:


> Hey, I could have a 1985 Casio for a brain and it would _still_ be Turing-complete.



But of course, those of us who are privy to the classified information RE: *THE BENJAMIN CLAYBORNE PROJECT *can state for the record that your supercomputer brain is quite a bit more advanced than a 1985 Casio.


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## Ravana (Jun 17, 2012)

Ireth said:


> I'm of the opinion that the "we only use 10% of our brains" idea is a myth.



It is… as has already been "ahemed" a couple of times. 

-

Queshire: Solar energy is so massively inefficient that we can't even get it to do _mechanical_ things well. Plants _do_ use it… and are not widely noted for their intellects. The problem is the amount that can be collected by a given surface area; for a human being, this would be a trivial increase in what was available. If anything, this is why organisms evolved to consume one another: usable energy exists in vastly greater concentration in organic matter. You can run a small car all day on one tank of gasoline; try running it all day on solar panels, and see how far you get… or how fast.

The telepathic suggestion, while promising to a certain extent (especially the idea of need-to-know lookup replacing storage), is, unfortunately, somewhat question-begging, as one would wonder what sort of mechanisms would have to be evolved to handle telepathy along with all the other things the brain already does. Of course, since telepathy tends not to get explained in terms of physical properties anyway, this could be (and almost always is) simply ignored; on the other hand, if one is trying to answer the question of how to make a species "smarter" without appealing to additional brain development, it doesn't constitute much of a solution… you could just as easily ignore the need for additional brain development in the first place. Barring that, it isn't a whole lot different from saying elves or whatever are "magically" intelligent.

-

Now some attempts to address the original question.… 

- Energy availability could be met by increased efficiency of processing (digestion, presumably). It might also be met by different diet: protein and carbohydrates provide twice the energy of fiber, ethanol three times as much (drink up, smart folks!  ), fat four times as much.
- Increasing the amount of energy available to–rather, used by–the brain would also increase the need for heat dissipation. This might be met by improved bodily mechanisms (most likely circulation, to carry more heat away), presumably combined with improved or added mechanisms for cooling the blood once it has been carried away. One of the easiest ways to make a species of higher intelligence might simply be to have them live in much cooler conditions. 

- Different neurotransmitter chemicals (or receptors, or both, or changes in the percentages of these) might provide increased efficiency of signals. 

- While the article seems not to regard increasingly modular brain structures to be much of a solution–one quote dismissively calls it "the backbends that the brain has to do to satisfy the connectivity problem”–I can't fully agree. For starters, obviously this tactic _has_ proven evolutionarily fruitful: the question then becomes the extent to which it can go further, and that question isn't even speculated about in the article. 
- If nothing else, some of the functions might be fruitfully rearranged to shorten pathways and thus save space and energy requirements. Why, for instance, is the visual cortex the _hindmost_ part of the brain–when the eyes are in the _front_ of the head? Especially considering the amount of information humans absorb through their eyes, as opposed to all other senses combined? Why is language processing scattered among several different areas… and why on the _outside_ of _both_ frontal lobes (creating seldom-used redundancy) rather than a centrally-located position?
- Along the same lines, does the corpus callosum provide any advantage–or, conversely, does the gap it bridges provide any advantages? Yes, humans lacking one demonstrate some cognitive differences and tendencies toward seizures… but while all vertebrates have lateralized brain hemispheres, only mammals (and excluding marsupials) have the callosum to aid communication between the hemispheres. It seems one ought to be able to do without one or the other.…
- To go in the other direction, there is no reason all brain functions need to remain in the head. Why not put the autonomic nervous system in the torso along with nearly everything it controls? Not only would it clear out space up top, it would shorten a _lot_ of pathways, thereby reducing the amount of energy the body uses overall, even if this isn't in the brain _per se_. Similarly, even cognitive functions might be "distributed": this would slow them down a bit, sure, but would allow much greater space… and perhaps allow for each space to be more densely packed, with neurons bearing more connections, thereby increasing speed again, albeit for each specialized function separately. Besides, speed isn't everything–it generally doesn't matter how quickly you arrive at a wrong answer. Or at least you won't impress anyone with your intelligence in doing so. (And it could have the happy side-effect of some people _actually_ having their brains in their… whatevers.  )
- If the longer signal-carrying paths were dedicated ones–i.e. single "wires" carrying signals that didn't need to jump from one neuron to the next all the way, or to scatter throughout vast networks of unrelated ones–this could speed function while conceivably saving space, though probably at the cost of losing a lot of those seemingly-random linkages we refer to as "insight." And probably a lot else we associate with intelligence: creativity might be another potential casualty.

- One might look at entirely different body (or at least brain) compositions: silicon-based, whether crystalline or optical fiber, for example. (Lest anybody object to the chemistry, it should be noted that a few Earth organisms do make use of silicon… albeit for structural components, not for neurons.) Possibly biochemistries with higher contents of certain metals could accomplish more efficient signal conducting as well; that one I'm less sure of. 

All that having been said, I tend to agree with the overall thrust of the article, which is that there is almost certainly a diminishing return on intelligence relative to brain size and complexity. I just don't feel they establish that we're anywhere near that. Who knows? Terrestrial life might have managed to evolve one of the _least_ efficient methods for handling cognition… maybe we don't need all those neurons after all, whether we make use of them or not. 

Besides, we've only been working on the problem half a billion years or so–and mammals have only had a serious go for barely a tenth of that, so who knows what kind of mistakes we haven't managed to corrcet yet?


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## shangrila (Jun 17, 2012)

Ireth said:


> I'm of the opinion that the "we only use 10% of our brains" idea is a myth. Maybe we only use only 10% *at a time*, but we have lot of different areas in the brain that have different functions. You can't just say 90% of our grey matter is totally useless.


Yeah, this has been proven. If you're interested, the misconception originally came from a misquote. The original guy said that we only use 10% of our brains at any one time, but when it got published that last part was cut off, creating the myth.


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## ALB2012 (Jun 17, 2012)

Phil the Drill said:


> I like thought-provoking articles like this, but elves will continue to be in fantasy regardless of whether it's possible for them to exist or not.  A giant flying lizard that breathes fire can't really evolve to be able to speak multiple languages, but those exist in fantasy also.



I was going to say that. I think its fantasy that is sort of the point You don't often get wizards either.


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## ALB2012 (Jun 17, 2012)

Ireth said:


> I'm of the opinion that the "we only use 10% of our brains" idea is a myth. Maybe we only use only 10% *at a time*, but we have lot of different areas in the brain that have different functions. You can't just say 90% of our grey matter is totally useless.



You havent met some of the people I work with


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## Robert Donnell (Jun 17, 2012)

First read about The Bell Curve:

The Bell Curve - Wikipedia, the free encyclopedia

You will see the human intelligence can go quite high.  2.5% of Humans have an IQ greater than 130, with a brain weight up to 1.400g.  Neanderthals had brains as large as 1,700g, so humans have some room to grow intellectually, I am guessing way past an IQ of 200+.


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## Fnord (Jun 18, 2012)

Robert Donnell said:


> First read about The Bell Curve:
> 
> The Bell Curve - Wikipedia, the free encyclopedia
> 
> You will see the human intelligence can go quite high.  2.5% of Humans have an IQ greater than 130, with a brain weight up to 1.400g.  Neanderthals had brains as large as 1,700g, so humans have some room to grow intellectually, I am guessing way past an IQ of 200+.



There's a can of worms waiting to be opened.  


In all honesty, I sort of groan whenever some expert or another comes out and says we have hit the limit of "X" in regards to humanity (whether X = population limits, civilization, intelligence, resources, wealth, innovation, etc) because people have been saying it for centuries in some form or another (Thomas Malthus is the most obvious example that springs to mind).  Humans are pretty damn resourceful and we're pretty good at "outsourcing" things, such as computing power, in ways that transcend physical limitations.  

But pessimism sells.


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