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History of Twins
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aversion, and in giving a fallacious sense of their being natural instincts.
But it will be observed that the circumstances from which these influences
proceed, affect large classes simultaneously, forming a kind of
atmosphere in which every member of them passes his life. They produce
the cast of mind that distinguishes an Englishman from a foreigner, and
one class of Englishman from another, but they have little influence in
creating the differences that exist between individuals of the same class.
HISTORY OF
TWINS.
The exceedingly close resemblance attributed to twins has been the
subject of many novels and plays, and most persons have felt a desire to
know upon what basis of truth those works of fiction may rest. But twins
have a special claim upon our attention; it is, that their history affords
means of distinguishing between the effects of tendencies received at
birth, and of those that were imposed by the special circumstances of their
after lives. The objection to statistical evidence in proof of the inheritance
of peculiar faculties has always been: “The persons whom you compare
may have lived under similar social conditions and have had similar
advantages of education, but such prominent conditions are only a small
part of those that determine the future of each man’s life. It is to trifling
accidental circumstances that the bent of his disposition and his success
are mainly due, and these you leave wholly out of account—in fact, they
do not admit of being tabulated, and therefore your statistics, however
plausible at first sight, are really of very little use.” No method of inquiry
which I had previously been able to carry out—and I have tried many
methods—is wholly free from this objection. I have therefore attacked the
problem from the opposite side, seeking for some new method by which it
would be possible to weigh in just scales the effects of Nature and
Nurture, and to ascertain their respective shares in framing the disposition
and intellectual ability of men. The life-history of twins supplies what I
wanted. We may begin by inquiring about twins who were closely alike in
boyhood and youth, and who were educated together for many years, and
learn
