INHERITANCE OF TEMPERAMENT. 1 05 



Wendt (1887) studied a case of identical twin sisters who became ill 

 about the middle of their third decade with a slight mania. One of 

 them was placed in a hospital and after 8 or 9 months discharged 

 recovered. The second sister was shortly afterward brought to the 

 hospital. In the symptoms of her illness, as in her outward appearance, 

 she showed such a close resemblance to her sister that one might have 

 been taken for the other. 



Baume (1863) tells of the twin brothers, Martin and Francois, who 

 lived, the former at Lorette and the latter 2 leagues away at Quimper. 

 On about the i5th day of January the twin brothers, who had placed 

 their savings in a common box, were robbed of 300 francs. During 

 the night of January 23-24, at 3 o'clock in the morning, they had the 

 same dream. Each awoke with a start, exclaiming that he had caught 

 the robber and that his brother was being hurt ; and both danced and 

 jumped on the floor in the same extravagant fashion. Martin, who 

 lived with his grandson, attacked the latter, fixing upon him as the 

 robber ; his excitement was progressive ; he complained of violent pains 

 in his head ; at 4 o'clock on the afternoon of the 24th he went out and 

 tried to drown himself in the river, but was prevented by his son; at 

 7 that evening he was received into the asylum, where he died on the 

 morning of the 27th. Meanwhile Francois spent the day seeking for 

 the robber; at 6 in the evening he came upon his brother struggling 

 with the gendarmes; became much excited; complained of a violent 

 pain in his head, and on the same day drowned himself in the river at 

 the same place where Martin, unknown to him, had attempted suicide a 

 few hours before. 



The foregoing histories of twins, which are quite in line with, and 

 doubtless largely inspired by, Galton's (1883) essay on the "History of 

 Twins," bring out in clear light the almost complete dependence of 

 temperament upon internal, hereditary factors. Since the same emo- 

 tional peculiarities develop in twins who are separated from each other 

 by miles or even oceans, i. e., who have undergone very dissimilar 

 experiences, we are forced to admit that of the factors that determine 

 mood the internal are the most significant. If a loss causes in me a 

 profound depression, that is my specific reaction to such a loss. The 

 loss is not the "cause" of the depression, but it permits my reaction 

 to such a situation to show itself. A rat causes one reaction in a fox 

 terrier and a different reaction in a collie dog. If the rat were the 

 "cause" of the reaction both dogs would act alike. The rat merely 

 starts a train already laid in the terrier ; it starts nothing, because there 

 is no train laid, in the collie. Similarly must we account for the differ- 

 ences in the reaction to the same outward event made by two persons. 

 The hereditary predisposition is always determinative. The great 

 weakness of the Freudian as a general explanation of emotional psy- 

 choses is that it lays too little stress on the constitutional factor. 



