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Tuesday, June 19, 2012

Intelligence: Of Ants and Men

According to the dictionary, "intelligence" means "capacity for learning, reasoning, understanding, and similar forms of mental activity".  Since it's a "capacity" sort of thing, there is therefore a range of intelligence, with some having more capacity than others.

Sometimes that range is compared to a threshold, usually arbitrary, above which the person or thing is considered intelligent.  For example, we might say, "she's intelligent but he's dumb as a rock", which just means that she exceeds some arbitrary level of intelligence, but he doesn't.  This assumes that a rock has zero or very limited intelligence (which may be a bad assumption given that silicon can be considered a type of rock).

When we consider the possibility of extraterrestrial intelligent life, we also compare it to a threshold.  We'd rather expect that the life, to be considered intelligent, can communicate, builds stuff, and probably lives in fairly large groups.  Of course, an ant colony qualifies as an intelligent life form by that description, and I've often wondered if aliens visited the planet, if at first blush, they could tell the difference between the intelligence of ants and the intelligence of humans.  We both scurry about, build stuff, communicate, have some understanding of the world, and act on that understanding to extract resources from the world to raise our young.

One can argue that ants don't actually "understand" anything.  They're just little machines and their behavior is completely emergent due to their simple "programming" interacting with the world.  That's true, but the same thing can be said of humans.  We're just bigger machines and our behavior is completely emergent due to our somewhat more complicated "programming" interacting with the world.  I believe that's also very likely to be true.

Let's look at it incrementally.  Humans certainly have "capacity for understanding".  How about other primates?  I'd say certainly.  Cats?  I'd still say certainly, but they're less intelligent than primates.  Mice?  Well, they certainly seems to understand that it's a bad idea to hang out around cats, but they're less intelligent still.  Ants?  I'd say an ant understands its world in a primitive way, but here we get to that arbitrary threshold thing where some will agree with me and some won't.  Roundworms?  I think most would say no.  Rocks? No.

By the above sequence, the level of intelligence according to an observer is clearly very closely related to number of neurons.  A roundworm has 302 neurons, an ant has about 250,000 neurons, a mouse has 75 million neurons, a cat has a cool billion neurons, a chimpanzee has two billion neurons, and a human has 85 billion neurons.

A neuron is a neuron is a neuron, regardless of species.  The more neurons, the more intelligent.  Intelligence is an emergent phenomenon from the activity of those neurons.  There really is no objective threshold that demarcates intelligence from non-intelligence or understanding from non-understanding (for example, you can't say any species with more than 97,423,014 neurons is intelligent, those with less aren't).

Intelligence for biological entities is all simply a matter of degree based on the number of neurons.


Peter said...

Intelligence for biological entities is all simply a matter of degree based on the number of neurons

Oh my. Bret, I've warned you before to be careful with that koolaid.

OK, smart guy, if intelligence is just a function of neuron counts, what determines stupidity?

Peter said...
This comment has been removed by the author.
Bret said...


Sorry. I should've said "Intelligence for biological entities is all simply a matter of degree almost completely based on the number of neurons."

Sure, how the brain as a whole is interconnected and how it is connected to the rest of the organism has some relevance as well. The range of intelligence in humans is really pretty small other than those with brain damage. Pretty much everybody learns to talk and communicate for example.

Peter said...

Oh sure, there are always a few extra switches and plug-ins to save you determinists when faced with the hard questions. My broader point, though, was that biological determinist explanations always roll off the tongue smoothly for positive attributes, but not so much for negative ones. It's fine to put the fact that we build neat things, write cool constitutions and paint pretty pictures down to all those busy neurons, but we also kill one another for vengeance and betrayal, harm ourselves with a number of vices, engage in mass slaughter and commit all kinds of crimes. Ants don't. My question is, do we do these things because we are deficient in neurons or because the neuron is not necessarily our friend?

Aren't you pretty much saying consciousness is a function of the number of neurons? Isn't that sticking you neck out a bit?

Bret said...

I think Intelligence is a two-edge sword. Probably more good than bad, but I agree that plenty of bad comes with it. It seems that predators are typically more intelligent than prey so I imagine that prey don't think (if they could think) that intelligence is such a wonderful thing.

I'm not writing about intelligence because I think it's wonderful. I'm writing about because it's interesting. I'm working towards defining artificial intelligence which is a subset of my field (robotics), but I find that I first have to explain what I think plain old natural intelligence is before I can jump to the artificial variety.

I think that consciousness is only remotely related to intelligence and is mostly a strange artifact resulting from the complexity of some mammalian brains. An entity could have a huge "capacity for learning, reasoning, and understanding" yet not be conscious. On the other hand, a fairly high-level of neural complexity is probably required for consciousness. So not really a function of the number of neurons, but rather an emergent phenomenon in some brains that have at least billions of neurons.

If I can't stick my neck out on my blog, where can I stick my neck out? :-)

erp said...

Bret, I'm relieved to learn that AI won't include consciousness which more than anything else IMO allowed us, for good and evil, become dominant. Without it we're just better looking ants.

Thanks for including cats in your list of smart animals. I could write a book on our new kitten's antics. In a few short months, he's scoped out his world and shaped it to his advantage and unlike ants, gets us to do his heavy lifting and provide him all the creature comforts he requires.

Good luck with this project. I hope you'll keep us updated.

Susan's Husband said...


I don't think you can have an entity with a significant ability to "understand" without consciousness because the latter is simply that same ability applied to self.


I'm not sure I understand your point. Of course things like war come out of our intelligence. In my field we call that a "sharp knife" because any knife sharp enough to work well on food is sharp enough to cut off your finger. Ny tool powerful enough to be useful is powerful enough to be dangerous. Intelligence is no exception and I don't see where any one makes such a claim.

Bret said...

Susan's Husband wrote: "I don't think you can have an entity with a significant ability to "understand" without consciousness because the latter is simply that same ability applied to self."

If you substitute "general" or "universal" for "significant" I might agree.

My dog has learned and understands that if I walk across the living room a certain way that I'm going to sit on the couch. When he hears me walking, he races across the house, beats me to the couch and sits next to where I usually choose to sit. His reward is that I usually pet him So he understands this particular scenario fairly well and thus exhibits some intelligence. Indeed, he understands many of the behaviors of his human pack and understands quite a few words.

On the other hand, he seems remarkably un-self-aware. He chases his tail and doesn't seem to understand that he's making it move. He barks at his reflection in the window as if another dog is intruding on his space.

I doubt he has consciousness in the way humans have consciousness if he has anything like consciousness at all. Yet, he understands us.

So while a higher degree of consciousness correlates with high intelligence, I don't think that they're inherently linked. My bet is that human consciousness is linked to the ability to deceive, trick, and manipulate others. Something dogs don't do.

Susan's Husband said...

That's not understanding you, that's stimulus response.

Bret said...

But that's the point. It's all stimulus - response. With a primitive entity, it's a simple response to a limited set of recent stimuli. An organism with a substantial brain mass has a set of complex responses to a wide range of overlapping stimuli that have occurred over a long time period. That complexity is what I (and I believe most others) observe to be "understanding" and "intelligence".

When my daughter exhibits more or less the same behaviour as the dog and comes to sit next to me on the couch for a hug or just to hang out, do we say it's just stimulus - response? I think not, even though at some level it probably is. Does it imply that she (or the dog) have a complete understanding of me? Of course not, because nobody has a complete understanding of me, not even me (or is it especially not me). But she (and the dog) have a partial understanding of me, and can predict when I'm going to sit on the couch. And it's an understanding of me, because if my wife exhibits a similar initial behaviour of walking towards the living room, neither my daughter nor the dog will begin moving towards the couch because they understand that she's probably not going to sit on the couch.

So it seems to me that yes, it can be just classified as stimulus - response, but it also involves "understanding". And between my daughter and the dog, the difference in the level of understanding me in this limited case is probably pretty similar. For example, neither my daughter nor my dog know why I've chosen to walk over and sit on the couch. In fact, chances are, I don't know why I sat on the couch - most likely, I just felt like it.