54 THE POPULAR SCIENCE MONTHLY. 



shall not endeavor to epitomize the many arguments pro and con in 

 respect to such views as these, but will merely recall, in partial justifi- 

 cation of them, the results of some inquiries into the life-histories of 

 twins * that I published a few years ago. I took two categories of 

 twins those who were closely alike in their infancy and those who 

 were exceedingly unlike and I traced their histories up to the date of 

 the memoir. It appeared that twins who were closely alike at the first 

 frequently preserved their resemblance throughout life, subject, I may 

 almost say, to the accident of a fever, or other serious illness altering 

 the constitution of one of them, and laying the first foundation of a 

 gradually widening divergence. I found not a few cases in which 

 twins residing apart and following different professions at home and 

 abroad still continued to live parallel lives, ageing in the same way, 

 and preserving all along the same features, voice, gestures, and ways 

 of thought. I also met with cases in which death had occurred at 

 nearly the same time to the two twins, and from the same disease. It 

 further appeared, as regards those twins who were born very unlike, 

 that in no case did their dissimilarity lessen under the influence of 

 identical nurture. They had the same nurses, the same tutors, the 

 same companions, they were reared in every respect alike, yet their 

 characters continued to be as dissimilar, and, I need hardly add, their 

 features remained as different as if they had belonged to totally dif- 

 ferent families. The conclusion to which I was driven by the results 

 of this inquiry was that a surprisingly small margin seemed to be left 

 to the effects of circumstances and education, and to the exercise of 

 what we are accustomed to call " free-will." 



It follows from such opinions as these, which appear to be gaining 

 ground in popular estimation, that it is highly desirable to give more 

 attention than has been customary hitherto to investigate and define 

 the capacities of each individual. They form his stock-in-trade, the 

 amount of which admits of definition, whereby he has to gain his live- 

 lihood, and to fulfill the claims upon him as head of a family and as a 

 citizen. So far as we succeed in measuring and expressing them, so 

 far almost in an equal degree should we be able to forecast what the 

 man is really fit for, and what he may undertake with the least risk of 

 disappointment. They would encourage him if unduly timid, or they 

 would warn him from efforts doomed to be wasted. 



What I propose to speak of in the present memoir are those meas- 

 urements of the bodily form and faculties that can, or apparently could, 

 be made with some precision, but the personal data in respect. to in- 

 tellectual and emotional capacities, and to special aptitudes and tastes, 

 require a separate treatment. The progress of the art of measure- 

 ment of the more purely bodily faculties has been by no means uni- 

 form. It has never been specially directed toward furthering the 



* " Journal of the Anthropological Institute," 1875 ; " Fraser's Magazine," November, 

 18*75. 

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