galton.org 167
History of Twins
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in some cases the resemblance of body and mind had continued unaltered
up to old age, notwithstanding very different conditions of life; and they
showed in the other cases that the parents ascribed such dissimilarity as
there was, wholly or almost wholly to some form of illness. In four cases
it was scarlet fever; in a fifth, typhus; in a sixth, a slight effect was
ascribed to a nervous fever; in a seventh it was the effect of an Indian
climate; in an eighth, an illness (unnamed) of nine months duration; in a
ninth, varicose veins; in a tenth, a bad fracture of the leg, which prevented
all active exercise afterwards; and there were three additional instances of
undefined forms of ill health. It will be sufficient to quote one of the
returns; in this the father writes:
“At birth they were exactly alike, except that one was born with a bad varicose
affection, the effect of which had been to prevent any violent exercise, such as dancing or
running, and, as she has grown older, to make her more serious and thoughtful. Had it not
been for this infirmity, I think the two would have been as exactly alike as it is possible for
two women to be, both mentally and physically; even now they are constantly mistaken for
one another.”
In only a very few cases is some allusion made to the dissimilarity
being partly due to the combined action of many small influences, and in
none of the thirty-five cases is it largely, much less wholly, ascribed to
that cause. In not a single instance have I met with a word about the
growing dissimilarity being due to the action of the firm freewill of one or
both of the twins, which had triumphed over natural tendencies; and yet a
large proportion of my correspondents happen to be clergymen, whose
bent of mind is opposed, as I feel assured from the tone of their letters, to
a necessitarian view of life.
It has been remarked that a growing diversity between twins may be
ascribed to the tardy development of naturally diverse qualities; but we
have a right, upon the evidence I have received, to go farther than this. We
have seen that a few twins retain their close resemblance through life; in
other words, instances do exist of an apparently thorough similarity of
nature, in which such difference of external circumstances as may be
consistent with the ordinary conditions of the same social rank and
country do not create
