Facets of Medicine (5)
By William Wetherall
A Japanese version of this article appeared in
Kokutai, 16(7), August 1995, pages 160-161
Genes make a difference, but so do surroundings. No two human beings are the same, nor are their physical or social environments. The variety of anatomical forms and physiological processes about the living body, and the diversity of circumstantial conditions and situations that the body must contend with, is truly incredible.
Some anatomical and physiological outcomes are determined entirely by genes, some by surroundings. Other effects, though, are result from an interplay of both genetic and environmental factors.
For example, metabolism--how the body burns the fuels that are pumped into its tank--is more a matter of genetics than of what is on the table. And body size, also mainly a matter of genes, is a major factor in determining how much energy the body needs. Yet some large people eat very little and get fat, while some small people can eat a lot of the same food and remain skinny.
At the same time, how much nutrition the body takes in--whether adequate, excessive, or insufficient--also contributes to body size. The amount of nutrition actually consumed, however, is a matter of both desire (a mental factor) and availability (a socioeconomic factor). And attitudes toward diet--what must be eaten, what cannot be eaten--vary as much within as between social and political groups and communities ranging from families to states.
Then there is gender--whether the body is equipped to produce ova and bear offspring, or merely impregnate. Men may be men, and women may be women. But all men are partly women, and all women are partly men. Some people are born with the organs of both sexes, or with the organs of one sex but with more of the hormones of the other.
Male spermatozoa may be faster swimmers, but female adults survive better in the water. In the tradition of male fetuses, which are more likely to be naturally aborted, male infants and children are more susceptible to early death from illness (deaths rates due to accidents, suicides, and homicides are also higher), and are therefore less likely than their female counterparts to reach adulthood. And male adults are less likely to reach old age.
Speaking of age, time has an impact in how the body grows and deteriorates, works or doesn't, anatomically and physiologically, that is, physically. Spiritually, some people grow old while they are still young, while the minds (if not the hearts) of some geriatrics are younger than those of some teenagers.
IQ, the ratio of mental age to chronological age times 100, is also thought to be a product of genes and environment. The genes an individual inherits may determine potential intelligence. But the environment provided an individual, particularly that of the family in which the individual is raised, determines to what extent one's innate intelligence is developed or applied. Some very bright people don't do well in life, while some people with dimmer brains are very successful.
All of the above topics involve an interplay between nature and nurture. The debate between "genetic determinists" and "environmental determinists", however, grows more intense when "race" and "ethnicity" are factored into the developmental process.
"Nature"--which means the genetic cards one is dealt at conception and holds in one's hands from birth to death--also includes what most physical anthropologists and geneticists call "race". Their are many concepts of "race", all of them scientifically vague and politically controversial.
The most popular concept postulates three major racial groups based on geographical areas--Africa, Europe, and Asia--although these regions are much to large, and much too interconnected, to have ever contained a population so highly homogeneous as to be of "one race". Even if "Asia" where limited to "Japan", to regard its population as "one ethnic group" would not reflect anthropological fact, but would merely express the "homogeneity myth" of Yamatoist ideology.
The terms that label lineal descent from the most representative peoples of these three vast regions--"black", "white", "yellow"--derive from perceptions of skin color traits that are highly unreliable as measures of "race". But the "ethnic" labels used in fields of medical and social science, including "Japanese", are equally as misleading. "Nurture"--which includes "culture" as an environmental factor shared by an entire group or community--is central to the concept of "ethnicity", which is more fashionable than "race" but, in politically correct usage, no less biological. In fact, what is commonly called an "ethnic group" is essentially the same as what some anthropologists and geneticists still call "race"--meaning any group that is mainly defined by lineage, and by the shared experiences of a common lineage.
The term "Japanese American", for example, is almost always used to denote someone who is considered "connected" with Japan genetically, not environmentally. Such usage presupposes that being "connected" with Japan is a matter of blood descent, not culture.
This same "racialism" is reflected in both popular and scholarly use of the word "Japanese". Hence expressions like "Japanese and Ainu" and "Japanese and blacks" frequent mass media and academic literature, as though "Ainu" or "blacks" cannot be "Japanese".
But suppose someone comes into your clinic and they are black. And this black patient is a citizen of Japan. Which means that he or she is Japanese, because the Constitution and the Nationality law state that being Japanese is a matter of citizenship, not race or ethnicity. So to what extent does this patient become an object of ethnomedical (including ethnopsychiatric) curiosity?
If we are talking about an hereditary disease like sickle cell anemia, yes, it may be fruitful to look at the patient's family history for lineal clues to the genetic origin of the clinical problem. But does it follow that skin color and surname necessarily imply an innate ability to consume large amounts of alcohol without facial flushing? Or predict attitudes toward, say, suicide?
The term "racial hygiene", though hardly the standard term today, is still being used by some researchers in Japan to refer to racially comparative studies of health and hygiene. The concept of "racial hygiene" was taken most seriously in Nazi Germany, but Imperial Japan also carried out ethnically comparative medical studies in its colonies.
In most countries today, including Japan, scientists do research, under the more fashionable banner of "ethnomedicine" and other "ethno-" hybrids, on how anatomical, physiological, and mental traits may vary according to "racial" or "ethnic" background. A lot of the focus has been on "hybrids"--people who represent genetic mixtures of "standard" or "reference" populations.
The ethnic majority Yamato population in Japan is geographically an amalgamation of East Asian races, and as a group it shares the East Asian racial propensity for Aldehyde dehydrogenase deficiency as a cause for facial flushing reaction to alcohol. But does this statistical fact mean that one can expect a Yamato Japanese individual to get red in the face after one glass of beer or tumbler of sake and otherwise be a poor drinker? I've lost count of the number of times that self-styled "international people" in Japan have expected me to be a strong drinker, simply because I happen to be of white European descent.
I think of such things every time I read a novel or see a movie or TV drama in which a "gaijin" is found dead. And some detective argues that it couldn't be suicide because Christians think suicide is a sin.