488 EVOLUTION, GENETICS, AND EUGENICS 



Tests showed, however, that they were very different in mental capac- 

 ity, the Canadian twin being decidedly the brighter of the two. The 

 difference was three times as great as the average difference of fifty 

 pairs of identical twins reared together, and even somewhat greater 

 than the average differences of fifty pairs of fraternal twins reared 

 together. Physically, the Canadian twin was much superior, weigh- 

 ing 102 pounds, as compared with 92 for the English twin, a great 

 difference for such small persons. They were strikingly similar in 

 height, build, features, hair and eye-color, and finger and palm pat- 

 terns. Also, they showed great similarity in their will-temperament 

 qualities and in emotional reactions. Thus the differences in environ- 

 ment had caused marked divergence in the physical condition of the 

 body and in mental capacity, but had left the emotional nature un- 

 modified. In every respect this case is the direct opposite of Muller's 

 case. 



Newman's second case consisted of two twin sisters, who never 

 heard of each other until they were about twenty-one years of age, but 

 came together through the lucky accident of an acquaintance of one 

 accosting the other by mistake. They were separated at eighteen 

 months, adopted by two different families, reared in much the same 

 stratum of society, but one had only grade-school education, while 

 the other went through secondary and normal schools and taught 

 grade school. These twins were physically almost complete duplicates 

 when examined, as similar as the most similar identical twins reared 

 together. The mental tests showed that the more highly educated 

 twin ranks far above her less educated sister, the difference being more 

 than three times as great as the average difference of fifty pairs of 

 identical twins reared together and even greater than the average dif- 

 ference of fifty pairs of fraternal twins reared together. In contrast 

 with this stands the fact that in all tests of emotional traits and of 

 temperament, the twins give the impression of being remarkably and 

 unusually similar. To summarize, these twins show a profound effect 

 upon mental capacity due to vastly different educational careers, but 

 physically and temperamentally they are nearly identical. 



Newman's third case consists of two young men, one of whom lived 

 in fairly large cities and the other in small country towns and villages. 

 They had been separated at two months and had never met until 

 they were about twenty-two years old, when one discovered that he 

 had a twin brother while looking over some old papers. By a little 

 detective work he located him. Their educational experiences were 



