For general health in husband and wife, classifying as very robust, robust, normally healthy and delicate. Miss Elderton calculated from Pearson's "Family Records" a relationship of + .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|
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 tuberculosis between spouses which has sometimes been called "marital infection."
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. Res. 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 Inheritance of the Diathesis of Phthisis and Insanity: A Statistical Study based upon the Family History of 1,500 Criminals," Draper's Co. Res. Mem., "Stud. Nat. Det.," 5, London, Dulau & Co., 1909.
- That such differentiation exists is strikingly shown by anthropological maps, for instance those in Ripley's "Races of Europe," pp. 300-334, 1900.
- "Pearson, K., Proc. Roy. Soc. Lond., Vol. 66, pp. 28-32; also Biometrika, Vol. 2, pp. 274-275.