Our integrated instrument composed of psychological type and somatotypes can be employed in two different directions. One looks upward to the questions that arise when we try to relate typology, and the psychology they embody, to philosophy and theology. I have traced some of these issues in St. John of the Cross and Dr. C.G. Jung. The other direction is to see somatotypes as the outer sign of a biochemical typology that is just beginning to dawn on the far horizon. The idea of a biochemical typology goes back to the four humors of the Greeks and has influenced the study of human differences ever since then, but it is only recently that the advances in the natural sciences are beginning to make it a real possibility.

In our search for a biochemical typology we are like someone who wants to put together a jigsaw puzzle but who first must find the scattered pieces and has no guarantee that the ones he finds even belong to the same picture. First of all, let's look at some attempts to create a biochemical typology.

In 1965 a California physician, Henry Bieler, wrote a book entitled Food is Your Best Medicine summing up a long career in which he successfully treated many patients by a program of detoxification and a typology that divided them into three basic types: the adrenal, the thyroid and the pituitary. Some of the characteristics of the adrenal type are already quite familiar to us. The lower jaw is heavy, solid and often protruding, the chest is broad and thick, containing a large heart and lungs. And Bieler comments: "the skeletal muscles are well-developed and have splendid tone. Fatigue is practically unknown to the adrenal type. His muscular endurance is spectacular." (p. 85) But this is not quite our old friend the mesomorph. "A member of the adrenal-type group has a phlegmatic disposition - easy-going, jolly, slow to anger, never bothered with insomnia, fear or 'cold feet'. He will often go out of his way to avoid a quarrel." (p. 85) Clearly this particular kind of mesomorph has moved considerably towards Sheldon's endomorphic pole.

Bieler describes the thyroid type as having delicate and finely molded features, a long, thin chest, graceful hands with beautiful fingers, and if the adrenal person is a draft horse, the thyroid person is a race horse. Again, we discover Sheldon's ectomorph, but in the form of a mesomorphic ectomorph. "Usually several streams of thought actually whirl through his brain at once, making concentration most difficult. He is frequently fatigued..." (p. 87)

Bieler's description of the third type, the pituitary, was left undeveloped. He has a large head and long arms and legs, but we don't learn a great deal else about him. In his practice, which was apparently very effective, Dr. Bieler would estimate the degree of functioning of each of these particular types in the individual, and he would rely heavily on detoxification and proper diet, and an awareness that people overindulged in foods "that are most toxic to them because of their stimulation value." (p. 153)

These suggestive ideas have been recently taken up by Elliott Abravanel who amplifies the description of Bieler's basic types, fills out the picture of the pituitary type, and adds for women a gonadal type. Abravanel's early work was directed towards obesity: "I studied carefully the relationships between foods and the glands, and on this basis was able to develop, for each type, the precise diet to enable people with that body type to lose weight most effectively." (Dr. Abravanel's Body Type Diet and Lifetime Nutrition Plan, p. 5) The adrenal type is Sheldon's endomorphic-mesomoprh, or Kretschmer's pyknic type. "They are solidly built, have square or round faces, strong, squarish hands and feet, broad shoulders and thick waists - body shaped for power rather than speed." (p. 24-5) Dr. Abravanel describes one of his adrenal type patients, a high-powered salesman:

"I heard his booming voice in the waiting room before I saw him, and he had all the other patients laughing. He is a good-looking man, with great energy, verve and an infectiously charming personality - and eighty extra pounds. I knew at once he was an adrenal type, for this body type has its own typical fat distribution. Where thyroid types balloon around the middle and remain slim in their arms and legs, A-types thicken all over, though they do put a great deal of their excess weight in front, in a pot belly." (p. 25)

It is the adrenal gland, in his estimation, that orchestrates the metabolism of this kind of personality, and with the thyroid type, which is Sheldon's mesomorphic ectomorph, it is naturally the thyroid that plays this role and creates a distinctive metabolism.

The pituitary type is described as having a head slightly too big for their body, a fat distribution which is spread all over, a childlike face and a stomach rounded like a child. The gonadal type has a larger, lower half of the body than upper. The pituitary type is described as intellectual, cool and detached, while the gonadal type is sensuous, warm and comfortable. But neither one of them are easy to visualize in terms of Sheldon's body types.

Each type has its own particular craving, its way of overstimulating its metabolism. The pituitary type wants dairy products, the thyroid type sweets and starches, the adrenal type meat and salty foods, and the gonadal type fats and spices. Dr. Abravanel's treatment of obesity has been to recognize the different body types, their particular food weaknesses, and to create a diet crafted to their own needs. Later Abravanel extended his insights about obesity to the more general field of health and fitness, and he recognized the importance of the gland that is next strongest, or has a secondary predominance in the physical makeup, for this accounted for the variations found among the various body types, and he even describes people who have gone beyond their original body type, not that it is no longer recognizable, "but their physiology appears to have a more general and more organized structure about it". (Dr. Abravanel's Body Type Program for Health, Fitness, and Nutrition, p. 345) This is curiously reminiscent of Jung's wholeness seen at the level of the metabolism.

Another modern pioneer in biochemical or metabolic typology is William Kelley. Kelley's earlier interests in nutrition came into sharp focus when he was diagnosed as having a metastasized liver and pancreatic cancer, and given only a short time to live. He developed a nutritional therapy that cured him, and which he describes in his book One Answer to Cancer. Later, when his wife was ill, he put her on his diet with disastrous results, and came face to face with the problem of biochemical individuality. Out of these experiences he formulated two basic principles that have governed his nutritional work: non-specific metabolic therapy, which is building up the whole body so that it can fight off the disease, and metabolic typing in which he describes a variety of different metabolisms. The metabolic types are divided into three broad categories based on the two divisions of the autonomic nervous system: the sympathetic or activating nervous system and the parasympathetic or inhibiting nervous system. According to the relative predominance of these aspects of the autonomic nervous system, Kelley describes sympathetic types, parasympathetic types and balanced metabolisms. Again, we can see strong traces in Kelley's descriptions of the familiar body and psychological types. For example, he says of the sympathetic types, "Their muscles are usually quite well developed and show good muscle tone" (Metabolic Typing, p. 3). They are also prone to high blood pressure and arteriosclerosis. He describes them as liking to make decisions, having explosive actions, being extremely active and angering easily. But Kelley pays little attention to the overall body type, and his lists of characteristics of the sympathetic type goes well beyond what could be attributed to the mesomorph or the endomorphic mesomorph, as for example, when he characterizes them as suffering from the cold, gagging easily and having poor circulation.

The parasympathetic types "have poor muscle tone. They are in general lethargic, slow, fall asleep easily. They usually have a good reserve of strength." (p. 6) They also have a desire to be cautious and are slow to make decisions and have slow breathing rates, and are inclined to obesity. They have very enlarged round chests, good fat metabolism and often feel sad or dejected. Here we can see the endomorph, but, again, the total picture is not clear. Kelley's balanced group falls roughly in between. He divides each of these three groups further and ends with a total of ten types that reflect not only sympathetic or parasympathetic dominance, but the level of metabolic efficiency. But even these ten types he found inadequate, and so he refined his classifications to describe the percentage of each type that exists in a particular individual. He also tried to come to grips with the question of the original genetic metabolic dominant type changing due to various stresses.

Kelley has apparently employed his two basic principles of non-specific metabolic therapy and metabolic typing to good effect in dealing with intractable degenerative diseases like cancer. Recently a book on his work by Tom and Carol Valentine has appeared entitled, Metabolic Typing: Medicine's Missing Link.

In each of these three biochemical typologies we see the difficulties that arise when the authors try to talk of types instead of basic elements or components that make up the various types, and their type descriptions could be clarified against the background of the more developed typologies of Jung and Sheldon. But their works represent a wealth of practical experience and therapeutic expertise that should not be neglected.

These individual efforts parallel, in part, the recent development of orthomolecular medicine. The word orthomolecular, meaning the right molecules in the right proportion, was coined by Linus Pauling in a 1968 article, "Orthomolecular Psychiatry", whose basic tenet was that individual biochemical needs vary greatly, and if the natural nutrients that the brain needs can be supplied, then many serious mental disorders can be more effectively treated. The modern roots of orthomolecular medicine can be found in the work of Abram Hoffer, Humphrey Osmond, and John Smythies, the insights of Roger J. Williams and the research of Irwin Stone and Fred Klenner, and many others.

Roger J. Williams, for example, was a biochemist, nutritionist and the discoverer of pantothenic acid. He had developed a keen interest in biochemical individuality, for he had once received a shot of morphine after a surgical operation, and instead of it putting him to sleep, it made his mind race from one thought to the next all night. Another time, working in his laboratory on the alcoholic consumption of rats, he found that it:

"(1) was highly individual (as were also their excretion patterns), and (2) was genetically controlled (as evidenced by the distinctive behavior of each inbred strain and the relatively small variation within inbred strains), and (3) could be increased by deficient diets and abolished by fortified ones..." (Biochemical Individuality, p. 173-4)

But he found that the idea of biochemical individuality had been largely ignored. He combed through the literature and culled what references he could find, and in 1956 produced his masterful Biochemical Individuality: The Basis for the Genetotrophic Concept. Here he shows in great detail the variations that exist between people in anatomy, endocrine activities, reactions to drugs, and in almost any kind of measurement of the body. In anatomy, for example, "the observed variations encompass all structures, brain, nerves, muscles, tendons, bones, blood, organ weights, endocrine gland weights, etc." (p. 45) People differ in endocrine activities. They differ, for example, in the size of the thyroid gland and the amounts of protein-bound iodine in the serum, and the retention of radioactive iodine. (p. 82) Even babies who have been fed largely on a milk diet exhibit distinctive excretion patterns. People differ in the way they react to alcohol, much like Williams' mice:

"An interesting way in which individuals differ in their response to alcohol is the reaction when a small amount (0.03 cc.) of 60 per cent alcohol is injected into the skin. In all individuals there is produced a localized weal about I cm. in diameter, but the reaction in the surrounding area varies greatly from individual to individual. In about 18 per cent of the cases tested, the surrounding area was unaffected; in the others the inflammation graded from a small very slightly pink corona to a highly inflamed area 4 cm. in diameter." (p. 109)

And not everyone has the same ability to adapt to changed climatic conditions. "One study indicates what might be expected, namely, that there is variation in ability to adapt metabolism to changed climatic conditions. Of 21 women examined, 13 showed a 6 to 11 per cent drop in basal metabolism when they moved from a temperate climate into the tropics; 8 on the other hand showed little or no change." (p. 120)

Williams amassed data in many fields, and it led him to his genetotropic principle. "Every individual organism that has a distinctive genetic background has distinctive nutritional needs which must be met for optimal well-being." (p. 167) And far from this being a hereditarian point of view, he feels it allows him to overcome the old breach between nature and nurture. "Understanding and appreciating what heredity distinctively does for an individual may make it possible to cope environmentally with his difficulties." (p. 169) And he is well aware of the important implications this genetotropic principle has for psychiatry. We vary in brain morphology and brain metabolism, and if we could understand our individual needs, we could try to meet them.

Men like Bieler and Abravanel had a nodding acquaintance with Sheldon's work, but that was all. Their attention was focused on the biochemical types. In orthomolecular medicine the early insights of Hoffer, Osmond and Williams, and others, have grown and coalesced into a penetrating understanding of the biochemical nature of many diseases and their treatment in a nutritional and ecological way. This is one of the most promising developments in modern medicine, but the whole field of orthomolecular medicine, like its counterpart in genetics, is so new and so involved in specifics, that it has yet to have the leisure to think in terms of biochemical typology. But the creation of a biochemical typology and its coordination with Sheldon's somatotypes and through them to Jung's psychological types is not a project that defies the imagination. We have met Humphrey Osmond before, both in the field of Jungian typology and, somewhat symbolically, playing the role of intermediary between Sheldon and Jung, and Roger Williams had this to say about Sheldon's work:

"Sheldon's extensive classification of body types constitutes an important contribution to the understanding of the human differences which make for susceptibility to numerous diseases. What he has done with body form is just a beginning; anatomical features such as those mentioned in Chapter III and VI need to be brought into the picture. Classifications need to be worked out at the physiological and biochemical levels." (p. 171)

Imagine if someone were to take ectomorphs, endomorphs and mesomorphs and administer Williams' alcohol injection test. Sheldon made reaction to alcohol one of his three-way traits that distinguished between the three temperaments. Would the ectomorphs react more strongly than the other somatotypes? Or is it really fanciful to talk about an ectomorphic thyroid type? Williams indicated human variation in the retention of a radioactive iodine. Would the ectomorph differ from the endomorph and mesomorph? G.P.S. Dubey and his associates administered 131 Iodine to 86 men of different constitutions, and measured the whole body retention of the radioactive iodine at the end of 24 hours. The ectomorph showed maximum retention, the endomorph minimum retention, and the mesomorph fell in between.

E. Arthur Robertson and his colleagues profiled 10 volunteers for 22 different substances during a 6-week period, and then examined the same subjects two years later.

"Using linear discriminant functions derived from the first five (or first 10) specimens from each subject, we were able correctly to identify 96% (or 100%) of the specimens collected during the remainder of the six-week testing period. Ninety percent of the two-year follow-up specimens were correctly identified when we used all the original profiles to calculate the discriminant functions. Deliberately mislabeled specimens were also correctly identified by discriminant analysis." (p. 30)

In essence, each person had a distinctive biochemical profile that remained relatively stable, and deviations from it could be indications of the beginning of disease. The authors, realizing how difficult it was to portray this wealth of information in numerical form, used various graphic techniques, the most interesting of which was the computer generation of faces. Each one of the substances measured created the shape of the upper head, or the width of the mouth, or the separation of the eyes, and so forth. From the point of view of a biochemical typology the results were intriguing. Each of the 10 subjects had his distinctive face. But between the 10 subjects there were also similarities. For example, the shape of the upper head was controlled by the dopamine-13hydroxylase and the sample could be broken down into the narrow or pointy heads, and the wide heads. Would it be possible to see biochemical introversion and extraversion graphically portrayed in these faces? If groups of ectomorphs, mesomorphs and endomorphs and groups of introverted intuition types, extraverted thinking types and extraverted sensation types were profiled by these methods, would the corresponding groups have similar biochemical faces?

Sheldon once estimated 1,000 individuals could be somatotyped by 2 men working together for 90 working days, and this time could be reduced to 30 days using the somatotyping machine. What would be possible today in the age of video cameras, computers, and advanced techniques for aerial mapping? Could somatotype poses be recorded by video and automatically analyzed by computer using, for example, Sheldon's trunk index method? The technical problems involved in such an undertaking could be resolved. What is lacking is the will to do it, and that could be generated by an understanding of somatotypes as a way to integrate information coming from various disciplines. Such an automatic determination of somatotype, if linked with the data generated by the automatic testing for various biochemical markers, would go a long way towards the creation of a biochemical typology. What I am suggesting is that a biochemical typology is not unthinkable. In fact, once we have begun to see in terms of an integrated typology of psychological types and somatotypes, we will read the news of scientific advances in neuroscience and genetics from a new perspective.

But do these rapidly expanding fields have any need of Sheldon and Jung? Don't they have the force of hard science on their side and therefore are replacing these earlier, more subjective, methods? Not at all. There is a tremendous need to integrate the bewildering variety of new information that is continually being produced by laboratories all over the world. And that's what typology can provide in terms of a framework that can bring this data together so it can interact and can be used effectively. The developments in these fields are so new that the question of typology has not begun to be asked. But let's go ahead and, working from both directions, attempt to make some small steps in building our bridge further. It has gone from Jung to Sheldon, and now we can trace what a biochemical typology would be like.

In a 1983 interview David Baltimore, the Nobel prize-winning geneticist, clearly indicated how difficult it is going to be to avoid the question of human differences:

"Scientists will discover many subtle genetic factors in the makeup of human beings, and those discoveries will challenge the basic concepts of equality on which our society is based. Once we can say that there are differences between people that are easily demonstrable at the genetic level, then society will have to come to grips with understanding diversity - and we are not prepared for that. Until now we have said, "We will assume there is no diversity because we can't measure it; we will assume equality But we're going to find very quickly that a true genetic analysis leads us to differences." (U.S. News & World Report, March 28, 1983, pp. 52-3)

Translated into our present context, we can say that previously it was possible to ignore men like Jung and Sheldon and pretend their work was subjectively inspired, but we are rapidly approaching a time when we are going to see the biological foundations of the differences that they described, and see them with a force and impact on our society that there will be no escaping. The psychological ramifications of this genetic revolution will be issues that are going to be vital and then the work of someone like Jung in dealing with human differences on the psychological plane will come into its own in a new way.

Once we are in the possession of the rudiments of an integrated typology we have a framework in which to look at the explosion of information that fills the popular media, and even the sports page, with news of scientific breakthroughs and the results of psychological studies. Let's look at some examples.

In 1983 the Pan American games in Caracas, Venezuela were marred when drug tests revealed steroid use, which led to the return of almost two dozen medals. But this was, and is, only the tip of the iceberg. William Taylor, a specialist in sport medicine, suggests that there are more than a million steroid users in the United States alone. And the anabolic steroids which are versions of the male sex hormone testosterone will soon be joined with other substances like human growth hormone in the athlete's black market pharmacopoeia. Taylor has already received dozens of phone calls from fathers willing to fly their children to his Florida office and pay thousands of dollars to have them hormonally manipulated with the chance they will grow an extra few inches. Many athletes are convinced that steroids offer them physical and psychological advantages: increased muscle mass, reduction in body fat, quicker healing, a desire to train and concentrate, and a general psychological high. But steroids have been connected with liver damage and heart disease, and of particular interest to our study of types is that these steroids seem to be a kind of artificial mesomorphy, not only physically, but psychologically. What would Sheldon have made of the following qualities that Taylor lists under the heading of potential psychological alterations induced in anabolic steroid-using men: increased aggressiveness, increased tolerance to pain, increased tendency towards one-track-mindedness, increased tendency towards "explosive" aggressive behavior. If many professional athletes are already physically and temperamentally extreme mesomorphs, the use of steroids will just make them more so, and make maintaining physical and mental balance an even greater chore. In women the use of steroids is complicated by the fact that some of the effects appear irreversible: increased facial hair, deepening of the voice, and various other physical and psychological alterations, which would put the woman athlete more at odds with the society she has to live in and with herself.

Steroid abuse and the potential for abuse of the other hormones that genetic engineering is making available will be all the harder to control because of the temperamental imbalances in our society. We worship mesomorphy and reward it excessively. We tempt our athletes to these dangerous and illegal procedures because we dangle in front of them large amounts of money and fame which depend on a fraction of a second more speed, or an inch or two in better performance. We pay no attention to the psychological imbalance that this can create in them, even without steroid use. We can't expect to feed our children a steady diet of masters of the universe and then turn around and imagine they will not take the chemical means that seem to promise that they, too, can become extreme mesomorphs. What is lacking is an overall sense of temperamental and psychological balance. Mesomorphy is just one of the basic temperamental components and it is inextricably linked with certain psychological disadvantages - as every aspect of temperament taken by itself is which must be compensated for by a program of individuation.

We are going to have an increasing ability to alter our physiques and personalities by artificial means. In the 1960s intuition and introversion came in vogue, no doubt in compensation to the placid and complacent extraversion of American culture, and it was induced by LSD and mescaline. But whether we are promoting introversion or extraversion by artificial means, they won't work, for there are no substitutes or shortcuts for the long and difficult process of personal development. Let's look at another example.

"At Duke University Medical Center, Susan Schiffman has been conducting blind taste tests in which more than 60 percent of her obese patients show an acute ability to recognize different tastes. "I'm sure there is a connection," Schiffman says, "between a keen sense of taste and a craving for flavorful food. Many overweight people need more variety and intensity of taste, smell and texture than thinner people do. If you deprive them, they'll keep eating. They're not satisfied."" (Reader's Digest, July 86, p. 34)

What immediately springs to the mind of the Jung-Sheldon typologist is the supposition that here it is a question of the endomorph who is a sensation type, a thought we can pursue in the work of Stanley Schachter. Schachter describes a variety of experiments, his own and others, under the title, "Some Extraordinary Facts About Obese Humans and Rats". If we make the assumption that the obese humans are primarily endomorphs, and therefore have an endotonic temperament and a personality type dominated by extraverted sensation, we can read these experiments from our own distinctive point of view. Schachter performed an experiment in which the subjects were fed roast beef sandwiches or nothing, and then sat in front of five bowls of crackers with the impression that they were conducting a taste test, when the experimenters were really going to determine how many crackers they ate. The subjects with normal body weight ate considerably fewer crackers if they had already eaten the roast beef sandwiches, as we would expect. But the obese subjects ate "as much as - in fact, slightly more - when their stomachs were full as when they were empty". (p. 130) Schachter and his colleagues came to the conclusion that for the obese the internal state was irrelevant to how much they ate, which was determined by the sight, smell, and taste of food.

This interesting result led to the review, as well as creation, of a variety of experiments that examined the conduct of obese humans and rats. The results indicated that the obese will eat more than the subjects of normal weight if the food is right in front of them, but less if they have to go look for it. And they will eat more if it tastes good but less if it tastes bad. They will eat more when the food is easy to get and eat less when the food is hard to get. And so Schachter concluded that they seem stimulus-bound.

His next step was to consider whether this state of being stimulus-bound was restricted only to food, or was a more general state of affairs. He found that the obese subjects could recall more objects that had been seen quickly, and were better in tests of complex reaction time in which there were two lights and two telegraph keys, and the subject had to lift his or her left finger when the right light came on, and vice versa. They were also more prone to distracting stimuli, "presumably, the impinging stimulus is more likely to grip the attention of the stimulus-bound obese subject". (p. 138)

The picture that develops is that these stimulus-bound people appear to have a higher threshold of stimulation. When the stimulus is present they react to it, and when it is absent they are much less active. This is similar to Sheldon calling the endomorphs biologically introverted organisms who need a certain level of stimulation to keep them going and bring them to a normal level of social interaction. Without it they tend to fall into inactivity. From the point of view of psychological type we would expect the extraverted sensation type to be keenly aware of his surroundings and highly responsive to what is happening to them. But he lacks intuition. He is oriented to the here and now, but finds it hard to motivate himself to work for what could be. And if he is stimulus-bound or geared to extraverted sensation, then he is highly distractible, for he has a hard time turning off extraneous stimuli and concentrating on the one task that he has set for himself. One of the facts about obese rats that bothered Schachter was that these highly reactive creatures were hyposexual, but this hyposexuality is one of the traits that Sheldon ascribed to the more extreme endomorphs.

In another study a team of Danish and U.S. scientists studied 540 adopted children:

"The evidence, as reported in the New England journal of Medicine, was unequivocal: the size of the children consistently reflected the size of the natural parents. There was absolutely no correlation between the body builds of the adoptees and their surrogate mothers and fathers. And these parallels held true in all weight classes, from skinny to grossly fat." (Newsweek, Feb. 3, 1986, p. 61)

There is no need to read this in the context of the old nature-nurture arguments. It's better to see obesity having a strong genetic component or dimension of endomorphy which predisposes the person to a difficult struggle to preserve a reasonable weight in a society that exercises too little and eats too many refined foods.

Another example. In an interview with U.S. News & World Report, psychologist Jonathan Cheek discussed his studies on shyness. He found it afflicted as many as 40% of American adults who have "a general tendency to be tense, inhibited and awkward in social situations, particularly in face-to-face interactions with strangers and especially with those of the opposite sex." (Oct. 31 , 1983, p. 71)

The percentage among the Japanese runs about 60%, and what is the reason for this?

"We feel that there is a genetic component to shyness for about 40 percent of the adults who suffer from the problem. In a study of high-school students I did with Alan Zonderman of Johns Hopkins University, we found that genetically identical twins are much more similar in their degree of shyness than are fraternal twins, who average only 50 percent of their genes in common ... Arnold Buss of the University of Texas has proposed a distinction between early-developing and late-developing shyness. The early-developing type is very much a physiological symptom. For example, a Harvard study found that infants who are shy and fearful when encountering strangers often have unusually high heart rates when confronting any unfamiliar situation. This indicates that the physiological component of shyness involves having a particularly sensitive nervous system.11 (p. 72)

In addition to heart rate this higher level of physiological arousal embraces upset stomachs and blushing, as well. This physiological shyness appears to be our old friend the introvert-ectotonic, and the 40% estimate in the U.S. population which Cheek presents elsewhere in the article as being between 33 and 40% fits well the MBTI and somatotype introversion percentage of 38%. The twin study brings to mind Sheldon's examination of 46 pairs of identical twins whose trunk indexes were identical within each pair.

In still another study Jack Block spent 20 years studying several hundred subjects followed from the 1930s by Berkeley's Institute of Human Development. He analyzed some of the extensive archives of material including attitude checklists and interviews which had accumulated on these people in order to try to determine whether their personalities changed with time. To accomplish this usually three clinical psychologists were assigned to rate portions of each person's record independently.

"Using this painstaking methodology, Block found a striking pattern of stability. In his most recent report, published earlier this year, he reported that on virtually every one of the 90 rating scales employed, there was a statistically significant correlation between subjects' ratings when they were in junior high school and their ratings 30 to 35 years later, when they were in their 40s." (Psychology Today, May 1981, p. 20)

Hints of this coming biochemical typology have appeared in Jungian literature, as well. Ernest Rossi in "The Cerebral Hemispheres in Analytical Psychology" reviews the left-brain research in which the left brain is connected with verbal and logical thought, while the right brain is more synthetic and spatially oriented, and tries to relate this brain laterality to various Jungian ideas, including psychological types. He associates extraversion, thinking and feeling with the left hemisphere, and introversion, intuition and sensation with the right, and he proposes the suggestive view that individuation or "the integration of hemispheric functioning may turn out to be one of the neuro-psychological foundations of the transcendent function". (p. 45)

In a comment on this paper J.P. Henry suggests broadening the framework to include the subcortical brain systems. Then it is a question not only of left and right hemispheres, but the affects that have to do with the lymbic system and the drives associated with the hypothalmus and the brain stem. Introversion and extraversion would be explained by the relative development of different vertical pathways and one hemisphere over the other. Under the heading of possible neurological basis for Jung's concepts Anthony Stevens in his Archetypes: A Natural History of the Self reviews these ideas in the context of an extensive study of the relationship between Jungian psychology and ethnology.

Attempts to relate introversion and extraversion to brain biochemistry are not new. In 1929, for example, William McDougall in an article entitled, "The Chemical Theory of Temperament Applied to Introversion and Extraversion" suggests that extraversion is a positive state which has a certain substance X while introversion is the lack of that substance. "The marked introvert is the man in whom the inhibition normally exerted by activity of the cerebral cortex on all lower nervous functions is manifested in high degree." (p. 22) This introversion is a result of the development of the cortex in man and so poses a danger that men will become excessively introverted and rendered unfit "for the life of action and unfit for social intercourse, for maintaining that sympathetic rapport with their fellows..." (p. 23) The substance X, then, becomes the antidote to this excessive introversion, and McDougall likens it to the effect of alcohol, which he describes as an extraverting drug.

In 1986 Ernest Rossi in The Psychobiology of Mind-Body Healing gives an account of recent developments in neuroscience in the course of forging an intriguing argument on how the cortex through the midbrain effects the rest of the body. His intention is to provide an explanation for the power of mind over body, whether in the placebo effect or in therapeutic hypnosis. He carefully traces the potential routes by which the electrical impulses of the neurons of the cerebrum reach the hypothalmus and limbic areas of the brain, and are converted then into various neurotransmitters that effect every part of the body via the endocrine, immune, and neuropeptide systems. Changes in the mind directly effect the body down to the level of the cell. Rossi calls this the mind-gene connection, for some neurotransmitters apparently actually enter within the individual cell and induce its genes to produce messenger RNA which creates various proteins. When we start thinking in terms of these kinds of mind-body systems, it becomes unthinkable that the body and temperament would not be intimately linked.

"What happens is that collaterals from the ascending sensory pathways produce activity in the ARAS (ascending reticulating activated system), which subsequently relays the excitation to numerous sites in the cerebral cortex." (p. 197) Then introversion and extraversion become "identified largely with differences in levels of activity in the corticoreticular loop."

Eysenck has proposed two theories of introversion and extraversion. The more developed 1967 theory indicated that the higher cortical arousal of the introverts was connected to the mid-brain and the ascending reticulating activated system. The common ground we saw between Jung, Sheldon and the factor analytic school can be described in an even more detailed way by examining the conclusions that the Eysenckian school of individual differences has arrived at. Here the introvert is considered to have a higher cortical arousal, while the extravert has more cortical inhibition. This higher arousal of the introvert is manifested and demonstrated in many ways. In EEG comparisons the introvert has lower amplitude and higher frequency of alpha waves than the extravert. The sedation level between them differs, as well. The introvert has a higher threshold and needs a higher dosage of sedation than the extravert. The extravert, on the other hand, has a higher preferred level of stimulation. The introvert, at least in certain experiments, has the longest tolerance of sensory deprivation, but he also has a lower tolerance of pain and a lower pain threshold. His sensory threshold, that is, the level he becomes aware of sensory inputs, is also lower, and his critical flicker fusion level, which is the degree he can maintain an awareness of the discreteness of the flickers of a light, is higher. What kind of picture do we get of the introvert and the meaning of this cortical arousal? He or she seems to be amplifying the sensory stimulation, but if the sensory stimulation gets too great, a process which Eysenck calls "transmarginal inhibition" sets in. The introvert seems to shut down and shut out the overstimulation.

These various laboratory measures of introversion and extraversion can be complemented by observations of introverts and extraverts in social situations. The extravert appears underaroused and therefore seeks greater personal intimacy and engages in more overt sexual behavior. He wants more social and physical stimulation, but since the introvert is already aroused, crowded and stressful situations like dealing with criticism or authority figures can overwhelm him. Introverts show higher levels of academic achievement and an interest in scientific and theoretical subjects, while extraverts show a desire for more social contact. Extraverts are less easily conditioned and apparently commit more crimes, though other factors like Eysenck's neuroticism and psychoticisin enter in here.

All these assertions are carefully qualified and discussed in various works like Eysenck and Eysenck's Personality and Individual Differences, but the assiduous reader of Sheldon can't help a feeling of dej5 vu. Isn't the introvert with higher cortical arousal the same as Sheldon's hyperattentional cerebrotonic who resists sedation, has a low pain threshold, and must devise continual strategies against overstimulation, or what Eysenck is calling "transmarginal inhibition"? There can be little doubt that what the factor analytic school is describing from an experimental point of view is the same personality differences that Sheldon described in terms of somatotype and temperament. What Eysenck and his colleagues do from a statistical and factor analytic point of view, Sheldon and Jung were doing at the level of the individual.

We may also note parenthetically that recent challenges to Eysenck's cortical theory of arousal based on the various circadian rhythms between introverts and extraverts show just how complicated Eysenck's theories must become to account for all the data. From the Jungian point of view this difficulty could possibly be explained by the existence of both introversion and extraversion in the one personality Another factor could be the different functions which will be somehow entering into these experimental situations and complicating the interpretation of their results solely in terms of introversion and extraversion.

We have seen that Sheldon's indications that the three basic components appear to be derived from the three layers of the embryo met with various objections on the part of Hunt and others. For example, Hunt suggested that the lungs, which derive from the endoderm, are equally or more developed in the mesomorphs. But most of his remarks are rather general. On the whole embryologists do not seem to have invested any substantial amount of energy in trying to verify or disprove Sheldon's thesis. Cortés, who looked into the question in some detail, undertook to summarize the present state of knowledge in an appendix to his book on delinquency entitled, "Embryological Foundations to Constitutional Types". Here he answers the hesitations of Hunt and Eysenck, and provides a chart of the three embryological layers. From the endoderm comes the digestive system, respiratory system, metabolic system and para-sympathetic system, and this metabolic system includes thyroid, thymus and para-thyroid. From the mesoderm comes the circulatory system, the muscular and skeletal systems, the sympathetic system and the genital system, which includes the sexual and adrenal glands. From the ectoderm there is the sensorial system, the central nervous system, the integumentary system of skin, hair, teeth, mammary glands, etc., and the central glandular system of the pituitary and pineal gland.

In addition to the early studies on intestine length and internal organs that Sheldon made use of and to which he added his own observations, Cortés adds the work of Reynolds and Asakawa who, with the use of X-rays, found that endomorphs had the most fat, ectomorphs the smallest amount of bone, muscles and fat, and mesomorphs the largest amounts of bone and muscle. And then Cortés raises two potential objections: if the thyroid comes from the endoderm, why do a lot of endomorphs appear to show a low degree of functioning? And the other objection is Hunt's question about the lungs: why do mesomorphs appear to have larger lungs than endomorphs?

And to answer these questions he turns to the work of Martiny who probably should rank as the person who has given the most developed view of the relationship between the embryological layers and body types. Martiny suggests that while diiodothyroxine in the thyroid is present in large quantities in the endomorph, its transformation, which activates the metabolism, is dependent on outside factors originating in the mesoderm and ectoderm which are deficient. In the case of the lungs, while they are derived from the endoderm, they are related to the circulatory system, and in this way have a mesodermal element. Martiny sets forth these views in considerable detail in his Essai de biotypologie humaine. This book was the fruit of 20 years of work pursuing body types from the point of view of the basic layers of the embryo, and what makes it even more interesting is that it was written independently of Sheldon's work, but shows a remarkable convergence with it. Martiny describes in detail 4 types: the entoblastique, the mesoblastique, the chordoblastique and the ectoblastique, with the chordoblastique representing the midrange physique. His basic descriptions of these types are so similar to Sheldon's as to dispense us from recounting them.

But Martiny goes beyond Sheldon and lays the foundation for what we are calling a biochemical typology. Let's assemble, then, some of his more suggestive remarks. The endomorph has an excess of qualities derived from the endoderm, but his mesodermal qualities are normal or deficient, and his ectodermal qualities always very deficient. The mesomorph has an excess of the qualities of the mesoderm, his endodermal qualities are normal, and ectodermal ones deficient. The ectomorph abounds in the qualities of the ectoderm, but those derived from the other two layers are deficient. These remarks fit well with the close relationship Sheldon found between endomorphy and mesomorphy, which, on a psychological plane is reflected in their common extraversion, and the distance between them and the ectomorph. Martiny relates this to the fact that the mesoblast derives not from the ectoblast, but from the endoblast. (p. 99)

While Martiny's anatomical descriptions match in detail Sheldon's they go beyond them in probing the physiology of each type. He suggests, for example, that the endomorph is the lymphatic type described in earlier literature. Not only does the lymph circulate slowly, but the cells of the endomorph exhibit a certain hydrophilia. Martiny finds a high incidence of hyperinsulinism and excessive functioning of the pancreas, together with a low level of metabolic functioning, despite the origin of the thyroid from the endoderm.

He notes that the steroid hormones are derived from the mesoderm, which explains the virility of this type (p. 117) as well as the development of their muscles and bone. He feels that among mesomorphs there is often a dysfunction of the pancreas and an elevation of uric acid in the blood. He writes, "The mesomorph is a hyperpituitary in whom the somatic hormone of horizontal enlargement of the metaphysis of the bone predominates over the hormone of growth of the pineal for vertical elongation." (p. 118) And he describes an experiment in which he injected small amounts of pineal extract in young rabbits, and in some cases saw them become gawky and long-legged. (p. 121)

In his description of the ectomorph he indicates that it is the excess of pineal function that explains his morphology, and notes how certain pineal tumors are connected with a long, thin body. He cites Chiray who insisted that ectomorphs have a blackish bile, which, if true, would be an interesting confirmation of the early typology of humors of Galen and Hippocrates. Martiny develops an explanation of the hypothyroidism of young ectomorphs leading to exhaustion, and suggests the special need that ectomorphs have for the B vitamins, enumerating B-1, B-2 and B-6, and perhaps in some prescient way anticipating the work of Osmond and Hoffer using B-3 in the treatment of schizophrenics. He suggests that the lack of vitamin B-6 is related to the muscular weakness, fatigue and insomnia found so often in ectomorphs. The ectomorph, while resistant to acute infections, suffers from chronic malaise, and a constitutional myopia that appears at puberty. Martiny also makes some tentative suggestions about blood types and body types: endomorphs B and some AB, mesomorphs B and some 0, ectomorphs 0 and A, and a little AB.

As far as we know, these highly suggestive remarks of Martiny have not been evaluated in the light of modern advances in embryology and biochemistry. However, the founding of the elements that make up the body types on the embryonic layers not only has a high degree of intuitive appeal, but the evidence that can be adduced for it seems at this point to far outweigh that which has been brought against it. And it is a promising road that should be explored in the future.