It is often possible, however, to reach useful conclusions from indirect evidence. If, for example, hereditary stocks which are not remarkable for crime and vice in one environment rapidly become so in another, we may believe that the environment is the factor most in need of correction. This is the case with the immigrant population in our badly governed cities. On the other hand, if we find that individuals of a certain stock generally turn out ill, no matter in what conditions they may be placed, the argument for bad heredity is strong. This applies to many studies of degenerate lines, for which Dugdale’s work on The Jukes set the example.
Where the matter is in doubt, as it must be in most cases, our line of action would seem to be somewhat as follows: If we are trying to better the conduct of living men and women, whose heredity, for better or worse, is already determined, we must proceed on the theory that environment is to blame, and try to better that. But if we are dealing with conditions that affect propagation, we should lean the other way. I mean that, if we find people living in a degeneracy which cannot clearly be ascribed to anything exceptional in the environment, we ought to hold the stock suspect, and prevent its propagation if we can. The cause that we have power over is always the one to emphasize.
The popular discussions of this matter proceed, for the most part, from a misapprehension of its nature. Heredity and environment are usually conceived as rival claimants to the control of life, and argument consists in urging the importance of one or the other, very much as boys’ debating societies sometimes discuss the question whether Washington or Lincoln was the greater man.
The views of even scientific men on this point have been for the most part crude and one-sided, owing chiefly to the fact that they have approached it from the standpoint of a specialty and without sound general conceptions. Biologists are apt to regard the stream of heredity as the great thing, and the social process as quite a secondary matter, important mainly as the means of a eugenic propaganda.[[52]] Sociologists, on the other hand, naturally exalt the process with which they are familiar, and seldom admit that the other is of equal moment. Both sides often seem to share the popular view that heredity and environment, society and the germ-plasm, are in some way opposites, so that whatever is granted to the one must be taken from the other.
Most of the writers on eugenics have been biologists or physicians who have never acquired that point of view which sees in society a psychological organism with a life process of its own. They have thought of human heredity as a tendency to definite modes of conduct, and of environment as something that may aid or hinder, not remembering, what they might have learned even from Darwin, that heredity takes on a distinctively human character only by renouncing, as it were, the function of predetermined adaptation and becoming plastic to the environment. In this state of mind they are capable of expressions like the following, from reputable authors: “Our experience is that nature dominates nurture, and that inheritance is more vital than environment.” “Education is to the man what manure is to the pea.”
Writers of this school are apt to think they have proved their case when they have shown that environment cannot overcome heredity; but this is as if one should argue that because a wife retains a personality of her own she must have conquered her husband. No doubt, what we get in the germ-cell is ours for life, and environment can only control, or perhaps suppress, its development. But it is equally true that heredity cannot overcome environment. If a man grows up in England no heredity will enable him to speak Chinese; and in general he must build up his life out of the arts, customs, and ideas supplied him by society.
Equally extravagant statements may be found on the other side; to the effect, for example, that heredity has nothing to do with crime. Socialists are apt to scoff at heredity because they wish to fix attention upon capitalism and other economic factors. Evidently what is needed is a larger view on both parts.
I might say that this topic affords a kind of pons asinorum for one phase of sociology, a test problem to determine whether an applicant is capable of thinking clearly in this field. If so, then no one has crossed the bridge who is capable of asserting, as a general proposition, that heredity is more important or more powerful than environment, or vice versa.
Such views are examples of the particularism that is so rife in social discussion, and is the opposite of the organic conception, the latter recognizing that the phenomena form an interdependent whole, every part of which is a cause of all the other parts. The particularist follows the line of causation from one point and in one direction from that point; the organic thinker sees the necessity of following it from many points and in all directions.
The lack of a good nomenclature is a serious bar to clear thinking upon these matters. How can we differentiate the biological and social processes when nearly all the words in general use may mean either? Although “heredity” is coming to be understood chiefly in a biological sense, there is a far older usage in the sense of social heirship, which is established in law, and not likely to be abandoned. And the noun “inheritance,” the verb “to inherit,” the adjectives “hereditary” and “inheritable” are used indiscriminately and smother the distinction. It would seem that the biologists, as the later comers, may fairly be called upon to give us new terms for the process they are bringing to light.