Anson uses eight different plates to show the common variations of human hand. He has to use no fewer than twelve to show the human heart in its commonest variations (there are people who have written of the heart who say that it is if anything more variable than the human face—an amazing statement when you consider how variable is the human face).
There are many other ways in which human beings vary anatomically. Take, for example, that very important organ, the intestine. In long and skinny people, as compared with round, soft people, the difference between the weight and length of the intestine is something fantastic: the intestine in the fat person may weigh twice as much as in the thin person and may be at least 50 per cent longer; it is consequently a great deal more efficient in doing its job, which is why the fat person tends to become fat even when he eats little, whereas the thin person does not become fat even when he eats a great deal. We find the same kinds of differences in the ductless glands.
The pituitary can weigh from 350 milligrams to 1,100 milligrams in perfectly normal people. The thyroid can vary from 8 to 50 grams, the parathyroid from 50 to 300 milligrams, the male gonad from 10 to 45 grams. The ovaries may range in weight from 2 to 10 grams, and the number of ova contained in normal ovaries may vary from as few as 30,000 to as many as 400,000. The pineal gland can weigh as little as 30 or as much as 400 milligrams and a normal pancreas can have as few as 200,000 Islands of Langerhans, or as many as 1,800,000.
Similarly, there are great differences in physiological reactions. As experimenters in taste perception such as Albert Blakeslee recently pointed out, there are substances which some people taste as salt, some as sour, some as bitter, and some as sweet. There are also enormous differences in the acuity of peripheral visual perception. In general we can say that these indubitably genetic anatomical and physiological differences are of immense importance because they must be reflected to some extent in our mental and psychological life.
The enormous mental and psychological differences which we perceive among human beings are correlated, first of all, with differences in the structure of the nervous system. It is quite certain, for example, that brains are very different from one another in the number, shape, and arrangement of their neurons. Although we don’t know exactly how these physical differences affect people psychologically, undoubtedly there is an effect upon our way of thinking and our character. The second genetic correlate of character and temperamental differences is the difference in the capacity of different individuals to produce various of the enzymes which control metabolism and nervous action. It is becoming clearer and clearer that this is a matter of immense importance. The third correlate is probably blood supply, which is likewise of great importance and which varies greatly among human beings: some people’s hearts pump much more blood than others and much more rapidly, the arteries in some are more efficient in carrying blood to different parts of the body, and so forth. Thus we have here the genetic basis for many of the psychological differences which we see; they are not determined by environmental factors alone.
One of the reasons why modern psychiatry has so astoundingly neglected the genetic factor in psychology is precisely because it has neglected the bodily factor in man. If you examine the body it is perfectly clear that there are enormous genetic differences between human beings. But if you ignore the body and concentrate solely on psychological traits, then this is not so obvious, although by inference it is perfectly clear that the enormous physical differences between human beings must be reflected in psychological differences. I am always astounded, when I read the literature of modern psychiatry, to see that the founding fathers of the science, Freud and Jung and Rank, paid almost no attention at all to the physical side of human beings and therefore completely ignored the genetic side of their problems. You can read the so-called case histories, and never be told who the subjects are. You get a description of Mrs X but you are never told if Mrs X weighs 90 pounds or 250 pounds; yet there is obviously a considerable psychological difference between a woman who weighs 90 pounds and one who weighs 250. Here is Mr Y, who is in a bad way, but you are never told whether Mr Y resembles an ox or a daddy-long-legs, whether he is like a panther or like a jellyfish. This obviously makes a prodigious difference, but one can read book after book of modern psychiatric case histories without ever finding such obvious facts mentioned. Only in Adler do we find some references to the physical aspect of human personality.
As it is very important that the doctors of the body should realize that the mind has effects upon the body, so it is important that psychologists should realize that the body has effects upon the mind, that many of these bodily effects are obviously genetic in character, and that therefore there are hereditary factors in practically all psychological disturbances. The most obvious case in point, which as far as I know is never discussed in the psychiatric literature, is the question, If all our psychological troubles are due to traumatic experiences in childhood, why aren’t we all crazy? We have all had very grave traumatic experiences, and yet only some of us are crazy and quite a number remain relatively sane. Again, it is quite obvious that such phenomena as Oedipus and sibling rivalry must act upon a biological substratum which is different in different cases.
There are certain people who have no psychological resistance, just as there are certain people who, undoubtedly for genetic reasons, have very little physical resistance to infection. This is of immense importance, for, as we can do something by biochemical means to correct a lowered resistance to infection, so it is perfectly possible that we might, by biochemical or nutritional means, do something to correct or to mask the genetic anomalies that make certain people much more likely to be affected by a psychological trauma than others are. Unfortunately, one finds almost no reference to this at all in the psychological literature; there is instead a kind of dogma, which may be called the dogma of environmental determinism, which almost systematically ignores the physiological factor.
This state of things is not universal and I am glad to say that within recent years there has been within psychiatry a strong unorthodox movement towards what is called constitutional psychology. The pioneer work in this field is being done by William H. Sheldon and his collaborators, as well as by George Draper and C. W. Dupertuis (in the field of constitutional medicine), who are investigating the relationship between disease and certain hereditary body peculiarities.
What Sheldon has shown is that we are perfectly wrong in thinking of ‘types’ of human beings. The trouble is that the nature of our language is such that we like to think in terms of pigeonholes and substantial types, and it is very difficult to talk about a continuum of any kind. In the world of physics, when people had to talk about the universe as a continuum, they had to invent a special ad hoc language, the language of calculus, and other forms of mathematical language. The same thing happens in psychological problems. As Sheldon has shown, and as is perfectly obvious must be the case, human beings do not vary by jumps and therefore cannot be put down as one type or another. Rather, there is a continuous variation among them; and this is not a variation between two poles—we always have a frightful tendency to think in terms of dichotomy—but it is much more realistically described as being a continuous variation within a three-pole framework.
I cannot go into the Sheldonian classifications today, but I do think they are extremely realistic classifications, and that his system does to some extent help us to see how the different genetic variations between body type and temperament—the relationships between physique and character—have always been intuitively understood by dramatists and story-tellers. No dramatist is sufficiently idiotic to put the character of a Falstaff in the body of a Cassius; no storyteller would give the character of a Pickwick to the body of a Scrooge. The logic of Caesar’s speech in Julius Caesar is perfectly obvious to us:
Let me have men about me that are fat,
Sleek-headed men, and such as sleep o’ nights.
Yond Cassius has a lean and hungry look,
He thinks too much: such men are dangerous.
Cassius thinks too much, but he is unlike what Sheldon would call the extreme ectomorph who thinks a great deal but never acts, or acts only feebly. He is one of those extremely dangerous persons who think a great deal and have enough of what Sheldon calls the ‘mesomorphic factor’ to act very strongly and efficiently—and too little of what he calls the ‘endomorphic factor’, the factor of geniality and of outgoing jolliness and kindness. Cassius is
