Why aren't most animals evolved to be as smart as humans?

Question

Considering humans are a relative newcomer on the world-scene and the benefit of intelligence is greater than any other evolved attribute as is clear by our dominance over every other species, you would think that many animals would have a humans level of intelligence or greater. Some animals are smarter than others but no animal comes close to humans. I wonder why?

It is upsetting to me that most people are simply regurgitating their basic understanding of evolution. I do not care what other attributes any animal has, higher intelligence will always give the animal an advantage in almost any environment to protect itself and provide itself with more food. I might buy some of these arguments for why some animals did not evolve high intelligence but I have heard nothing that explains why none of them have. Think people!

Again, people are simply trying to showcase their understanding of evolution and the complications involved with having higher intelligence. Some people have suggested that I am wrong for thinking we are smarter than the animals. Some people have even said that intelligence is not a favorable trait. Most have avoided the question all together. I am not asking what are the difficulties involved with having high intelligence. I am not asking why ALL animals are not as smart as humans. I am asking why NO animals approach being comparably intelligent. Some have tried to explain how costly a large cumbersome head is for an intelligent animal which does not answer my question but at least tries to emphasize why intelligence might be difficult to evolve. It is nonsense though. Humans use less than 10% of their brain thus much of our brain is wasted space anyhow. A more compact design is certainly possible. There are people living with half of a brain today that could answer this.

Answer 1

Higher intelligence has a price: brain size. The brain requires a lot of resources and makes the head cumbersome. Human infants are born with a brain that isn't finished, so it's completely helpless at first. It takes a year and a half before they can even walk. A human with a fighting chance against a wild animal will take at least 12 years to produce.

It's an interesting question that I'm going to look into further. My assumption is that we humans simply dominate every environment and that we have killed off any vulnerable threats like the Neanderthals, but it's hardly an answer.

Answer 2

I believe the answer to your question is that animals only evolve enough IQ to survive and reproduce and not a smidgeon more. The reason is that there is simply no need to go higher on the IQ scale if you are already successful at survival and reproduction. As a general rule, "Punctuated Equilibrium" rules the evolutionary world, with long, long periods of morphologic stability due to just this principle. When a species such as a clam, for instance, is fat and happy and doing well, what is the stimulus to radically alter the gene pool of such a species? Evolutionary change only occurs at a decent clip when the species is pushed to the brink of extinction, forcing an "evolve or die scenario". Our own species did not even begin to evolve higher intelligence until the last 2,000,000 years of our existance. For the 5,000,000 years or so before that, we were simply "chimps that walked upright" and certainly no smarter than chimps of today, in all likelihood.
I am an MD and I think you are overlooking the exteme disadvantages that intelligence confers upon us as a species. First of all, the human brain consumes about 25% of the total cardiac output, far higher than any other species. When running away from a leopard who is chasing you, do you really want to send all of that blood flow to a gigantic overgrown brain? Sending most of it to the muscles might be far better, don't you agree? And the brain itself is so big that even at this blood flow rate, we are continually on the verge of inadequacy of blood flow, even in a healthy person. This is why we are the only species that faints, and the only species that suffers from strokes in our old age, by and large. The brain in any species is about 95% phosholipid, which is a very calorie rich constituent. A human child has to eat and then store four times the high calorie phosholipid that a young Chimpanzee must, during normal growth and maturation. Where does a human child obtain all of those calories? What a burden to his parents! And then there is the childbirth issue. The human brain is so huge that it is nearly impossible to pass the baby out through the birth canal. In primative times the death rate from childbirth was ~5% PER delivery! No wonder that human males find wide hips on females to be attractive. And I do think I could go on and on.....

Answer 3

'Intelligence' is one of the more slippery concepts. Like 'consciousness', it's one of those things we all recognize, but have an incredibly difficult time defining. Even among the various different environments that Man inhabits, intelligence takes on many different meanings.

Compare, for example, an American with an Australian Aborigine. If an American walks into a room anf the corners of it are not within a very few degrees of exactly square, they'll notice it. But an Aborigine won't. OTOH, if an American sees the same bush 2 days in a row, they won't notice any difference except the most gross and obvious ones. But if only one leaf on the bush has been moved or pulled off, the Aborigine will spot it instantly. (And, BTW, that experiment *has* been done, many times. It's a classic in the world of Psychology) So which of the two is more or less 'intelligent'? The answer is, they'r both probably about the same, but in different ways.

The Stanford-Binet IQ test measures three (3) things: Reading Comprehension, Mechanical Aptitude, and Spatial Comprehension. But is that all that there is to 'intelligence? How about 'empathy' or 'artistic appreciation' or 'spirituality'? Those (and a couple of others) are all recognized (with a bit of bickering over definitions and meanings ☺) by the psychological community as being perfectly valid measurements of 'intelligence'. And notice that, so far, I've only been talking about 'intelligence' in one species. One species with nearly identical wants and needs within 'all' of it's various social and cultural settings.

How much more difficult can we imagine it to be to try and measure 'intelligence' in a totally different species which has little or nothing in common with ourselves? Certainly one can always fall back on the old Darwinian imperative and say that 'survival of species' is the fundamental measurement of intelligence in any species. But, by that measure alone, bacteria and virii are probably the most intelligent creatures on the planet ☺.

There is, as you mentioned, a lot of work that indicates that some animals are 'smarter' than others. But I would offer that a great deal of what's *really* being said is that some animals have an intelligence that is more nearly like ours, in some way(s), than do others.

All that being said, it's true that we *do* have a couple of things going for us that the other animals may not. We seem to communicate better (especially 'abstract' communications), but until we really understand the things that are most important in the life of a dog (or a dolphin) how will we ever know that they don't communicate 'abstractions' about the things which are most important to them? I recently read something about whales from different parts of the world seeming to have different 'accents' (or, perhaps, even 'dialects') in the sounds they make to communicate. It's an interesting thought.

Written language is also a big item. And yet there have been numerous civilizations in the past which were quite advanced in many ways, but which had failed to develop a written language. (Native Americans are an excellent example).

And, of course, if we have this much difficulty recognizing 'intelligence' in species that evolved along with us on the same planet, how much *more* difficult will it be when we finally do meet up with an extra-terrestrial life-form. Believe me, NASA spends quite a few research dollars in that direction. Or what if we find a life-form that is 'telepathic'? It's not as far-fetched as you may think. Quite a bit of research in 'consciousness theory' (especially some done here, in Tucson, at the University of Arizona) indicates that certain structures (called 'microtubuoles') in human brain cells may be capable of interacting with local quantum fields (which may explain the 'flash of insight' phenomenon). And, it turns out to be true, the implications are simply mind boggling in their profundity.

Anyway...... Those are just a few random thoughts that come to mind. Maybe they'll give you a bit more to think about, research, wonder over, etc. ☺

Doug

Answer 4

I would say it is luck of the draw. Evolution does not occur to fit an environment. It is more that the environment happened to fit the mutation that occured which resulted in an increase of fitness. One would think that other animals would be as intelligent as us, but there are many factors that come into play. If you become extremely evolved to fit a habitat and that habitat changes, you can become extinct from being overly specialized

Dominance over every other species is relative as well. Pound for pound, 1 on 1 we can not hold our own against similarly sized animals. That is why social skills were such an increase in fitness for our ancestors. We are puny, and if we don't work together we die. Those that were more robust in terms of social dynamics are the ones that were naturally selected. In other species the evolutionary advantage was more physical.
Evidence for this is the very quick growth of the portion of the brain responsible for social interactions and behavior prediction.
People often get confused on evolution. We did not evolve from monkeys, we have common ancestors with monkeys. Evolution is random, giraffes did not get long necks from stretching them. What happened is the giraffes that happened to have a mutation for increased neck length had an increased fitness to their environment.

Answer 5

Why should they? What selection pressure would have drove the enlarging of their brains, when they are fully functional in their niches. Intelligence is not a goal; evolution has no goal, does not progress and has no direction. Intelligence may even be a spandrel. I, think rather it is the result of our intricate social system, coupled with the beneficial mutation at the right time in the right environment. With benefits come cost and our brains are surly costly to maintain. Does not matter when we got here; just matters what selection pressure drove our big brain.

PS A lot of good answers here. I suggest you get off that progressive, superior look at evolution and read them more closely.

Answer 6

Here is your mistake:

"higher intelligence will always give the animal an advantage in almost any environment "

No. No. No. Only a human would make that simplistic assumption. "We got it, therefore it must always be advantageous."

Sometimes speed is more important (brains weigh you down). Sometimes smallness (brains are big). Sometimes lightness for flight. Sometimes strength. Sometimes venom. Sometimes a long neck. Sometimes a big bright purple tail. Sometimes the ability to slither inbetween rocks. Etc. etc.

Even in primates, a big brain is in many ways a *disadvantage*. Human babies are one of the most helpless offspring at birth. Why? Because human babies have to be born, essentially prematurely because the fully developed brain is too large to fit through the human birth canal. Why did we survive? Because humans compensated by becoming very good at protecting babies for longer.

It is *WAY* too simplistic to just say "smart is always better" ... there are *so* many things that contribute to the development of a specific trait ... different environments, different social structures, different mutations that enter the genome, different physical structures (like the opposable thumb, or the vocal cords that led to language and subsequent explosive growth of brain size).

It is as self-centered to wonder why other animals aren't smart like us as it would be for giraffes to wonder why other animals have such ridiculously short necks.

Answer 7

You seem to be irritated with people's answers yet you fail to give any specific examples in your question/information as to why you think your statement is true. What makes you think that humans are the smartest or most intelligent beings on the planet? If you compare the brain sizes of certain animals with the "intelligence" that they posess, you may be shocked. Certain ant species, rodent species and nonhuman primate species have astounded biologists and researchers with their learning abilities. How is intelligence the greatest benefit to a species? Humans kill others of their own species. How is that intelligent? Just because humans figured out how to go to the moon or build a computer does not necessarily make them the most intelligent being on the planet. In order for a species to prosper and survive in this world, its members must continue to live and thrive. And certain aspects of our intelligence that you may view to be of such a great benefit may actually be hurting our species in the end. While medical advancements are great in some aspects, millions of years from now, if we don't blow the planet up before then, our species will be overrun with humans with medical issues. In nature, organisms with disease die, so as not to keep that diseased organisms reproducing in the community. Humans treat and try to cure these diseases and as this goes on, our species will not be able to rid diseases from the species. I think you should do a little more research.

Answer 8

For one, Evolution does not follow any set path or lean toward any set goal. I'm sure if dolphins can think, they think we're ridiculous and less evolved since we still rely on "legs" and "arms" and have to create artificial clothing because our external defenses are poor. Haha.

For intelligence to come about, numerous things had to happen. Most of these things were directly related to bipedalism. Since humans could not run as fast as predators, they had to learn to outsmart them. And since they weren't as strong anymore, they had to learn to out-think prey to eat.

Intelligence came at the cost of other things. For one, our babies are born sooner and less developed than other species (where they can walk within days). We have to take care of them for a long amount of time, at least 5-10 years, before they function alone. This would not cut it in the wild, where it is eat or be eaten. Also, humans are not nearly as strong as any of the living apes.

Besides, I'm not always impressed with human intelligence. We'll probably be the cause of the end of the world. Sigh.

Answer 9

Well, different animals have different niches to survive. Giraffes have long necks to reach the leaves other grazers can't reach, and they invest energy into the long neck. Having a long neck is an expensive and risky proposition. If there aren't any tall trees, the long neck actually hinders, and the energy that goes to building and maintaining the neck is expensive.

So goes it with the brain. It's a huge investment energetically! We use a lot of energy to create and maintain our big brains, and it's also very vulnerable. We've traded away our claws and defenses (well, no one can say that, but I am supposing) for a brain! It is our tool, our niche and it is expensive to maintain, but it's worked for us. If I were in a pit with hungry tiger, probably the investment of brain would be worthless to us and we would have been better invested in legs to jump or claws and teeth (in a hypothetical world, this is my point). Our only goal really, biologically, is to mate and reproduce successfully, so energy is oftentimes directed towards that goal. As humans we are unusual that we have excess food (energy).

Anywho, for me BIG BRAINS RULE and are totally worth the energetic investments! I hope that answers your question.

Answer 10

Because humans are the youngest species and have the most evolution of the brain. Also the other animals do not need to be as smart as us to survive.