486 THE POPULAR SCIENCE MONTHLY 



For general health in husband and wife, classifying as very robust, 

 robust, normally healthy and delicate. Miss Elderton^^ calculated from 

 Pearson's " Family Eecords " a relationship of -f- .27. 



For freedom from constitutional diseases — i. e., freedom from any 

 specific pathological taint without regard to the strength or delicacy of 

 constitution — Goring^* found these resemblances for families of 

 criminals : 



Very poor and destitute + -17 



Well to do and prosperous poor + .08 



All + .11 



The possibility of infection reinforcing constitutional likeness in 

 consorts is presented by a disease like tuberculosis. From the evidence 

 now available^^ there can be little doubt that if one member (husband or 

 wife) of a pair be tuberculous the other is more likely to be affected 

 than if the first be sound. In short, there is a correlation for tubercu- 

 losis between spouses which has sometimes been called " marital infec- 

 tion." 



But such a term implies entirely too much. The correlations are 

 not so high but that one may suspect them to be due, in considerable 

 part, to assortative mating for the physical and psychical characteristics 

 which underlie, or at least accompany, the predisposition to tuberculosis. 

 Those who have analyzed the problem most minutely are inclined to 

 attach importance to both factors, but to lay especial stress upon 

 assortative mating. 



5. The Influence of Numerous Local Races 

 The reader who is a keen traveler will probably suggest that the 

 general population of England, whence most of the data have been 

 drawn, is made up of local races differentiated with respect to physical 

 characters,^® and that marriages tend to be contracted between neighbors 

 — i. e., within the local race. 



Pearson has emphasized the possibility of this factor^^ but with 



^^Elderton, Ethel M., "Stud. Nat. Det.," 3, London, 1908. 



"Goring, C, "Stud. Nat. Det.," 5, London, 1909. 



"' The three chief papers are : Pope, E. Gr., "A Second Study of the Statistics 

 of Pulmonary Tuberculosis: Marital Infection," edited and revised by K. 

 Pearson; with an appendix on Assortative Mating by E. M. Elderton, Draper's 

 Co. Ees. Mem., "Stud. Nat. Det.," 3, London, Dulau & Co., 1908. Greenwood, 

 M., ' ' The Problem of Marital Infection in Pulmonary Tuberculosis, ' ' Proc. Boy. 

 Soc. Med., Epid. Sect., Vol. 2, pp. 257-268, 1909. Goring, C, "On the Inherit- 

 ance of the Diathesis of Phthisis and Insanity: A Statistical Study based upon 

 the Family History of 1,500 Criminals," Draper's Co. Ees. Mem., "Stud. Nat. 

 Det.," 5, London, Dulau & Co., 1909. 



*° That such differentiation exists is strikingly shown by anthropological 

 maps, for instance those in Eipley's "Eaces of Europe," pp. 300-334, 1900. 



''Pearson, K., Proc. Boy. Soc. Lond., Vol. 66, pp. 28-32; also BiometriTca, 

 Vol. 2, pp. 274^275. 



