Extraterrestrial Civilizations - Isaac Asimov [7]
There is no question but that the elephant is among the more intelligent animals. In fact, the intelligence of the elephant is so apparent that human beings tend to exaggerate it. (There is a greater tendency to exaggerate the elephant’s intelligence than the ape’s, perhaps because the elephant is so different from us in appearance that it represents a lesser threat to our uniqueness.)
We do not have the opportunity to study whales as we do elephants, but we may readily believe that whales are among the more intelligent animals, too.
Yet, although elephants and whales are relatively intelligent, it is quite clear that they are far less intelligent than human beings, and may well be less intelligent than the chimpanzee and gorilla. How may this be squared with the superhuman size of their brains?
The brain is not merely an organ of intelligence; it is also the medium through which the physical aspects of the body are organized and controlled. If the physical size of the body is great, enough of the brain is occupied with the physical to allow little for the purely intellectual.
Thus, each pound of chimpanzee brain is in charge of 150 pounds of chimpanzee body, so that the brain-body ratio is 1:150. In the gorilla, the ratio may be as low as 1:500. In the human being, on the other hand, the ratio is about 1:50.
Compare this with the elephant, where the brain-body ratio is as little as 1:1,000 and the largest whales, with as little as 1:10,000. Now it is not so surprising that there is something special about human beings that the large-brained elephants and whales do not seem to duplicate.
Yet there are organisms in which the brain-body ratio is actually more favorable than in the human being. This is true for some of the smaller monkeys and for some of the hummingbirds. In some monkeys the ratio is as great as 1:17.5. Here, though, the absolute mass of the brain is too small to carry much of an intellectual load.
The human being strikes a happy medium. The human brain is large enough to allow for high intelligence; and the human body is small enough to allow the brain space for intellectual endeavor.
Yet even here the human being does not stand alone.
In considering the intelligence of whales, it is perhaps not fair to deal with the largest specimens. One might as well try to gauge the intelligence of primates by considering the largest member, the gorilla, and ignoring its smaller cousin, the human being.
What of the dolphins and porpoises, which are pygmy relatives of the gigantic whales? Some of these are no more massive than human beings and yet have brains that are larger than the human brain (with weights up to 1,700 grams, or 3¾ pounds) and more extensively convoluted.
It is not safe to say from this alone that the dolphin is more intelligent than the human being, because there is the question of the internal organization of the brain. The dolphin’s brain may be organized for predominantly nonintellectual purposes.
The only way to tell is to study dolphin behavior, and here we are sadly hampered. They seem to communicate by modulated sounds even more complicated than those of human languages, yet we can make no progress in understanding dolphin communication. They seem to show signs of intelligent behavior, even kindly and humane behavior, yet on the other hand their environment is so different from ours that it is difficult for us to get inside their skin and grasp their thoughts and motivations.
The question of the exact level of dolphin intelligence remains, at least for now, moot.
FIRE
In the light of the previous sections of this chapter, the question as to whether nonhuman intelligence exists on Earth must be answered: Yes.
It would seem that my contention early in the chapter that science has made us alone has not been demonstrated. There are a number of animals with surprisingly high intelligence, and these include not only apes, elephants, and