Page:Popular Science Monthly Volume 80.djvu/495

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491
ASSORTATIVE MATING IN MEN

For criminality, Goring's results will strike many as surprisingly low. They are:

Very poor and destitute. + .18
Well-to-do and prosperous poor not calculated
All + .20

An interesting point of an entirely different nature has been raised by Heron[1] who in a study of the distribution of sex in human families finds, "that in the free mating of man, families with a preponderance of female or male elements are not drawn upon equally with families in which the sexes are more equally balanced."

VI. Homogamy and Fertility

From the notion that in marriage "opposite poles attract" the step to the conclusion that dissimilar are more fertile than similar unions is so easy that it has sometimes been taken, though without any valid evidence in justification.

Fay[2] considers that marriages of the deaf are possibly slightly less fertile than those of hearing persons. When both partners are deaf the percentage of sterile marriages seems higher and the mean number of children in fertile mariageslower than in unions in which one member of the pair is a hearing person.[3]

Homogamy for stature[4] and for eye color Pearson (Phil. Trans. Roy. Soc., A, Vol. 195, pp. 148-150, 1900; Proc. Roy. Soc. Lond., Vol. 66, p. 323, footnote) has considered Galton 's data without arriving at final conclusions. De Candolle (fide Westermarck, "History of Human Marriage," p. 335) states that the number of children is considerably smaller when the parents have the same color of eye than when they were contrasted. Wittrock (Ymer, Vol. 5, pp. vii-ix, 1885) was unable, on Swedish materials, to detect any difference in fertility between the two classes of marriages. have been considered in relation to fertility.

But as yet the data are far too meager for such complex problems. The whole problem of the relationship between homogamy[5] and fertility is open to investigation.

VII. Significance of the Results

The statistical facts reviewed in this essay make it highly probable that a great variety of physical and mental characters influence human

  1. Heron, D., "On the Inheritance of the Sex-ratio," Biometrika, Vol. 5, pp. 79-85, 1907.
  2. Fay, E. A., "Marriages of the Deaf in America," pp. 16-18, 29-30.
  3. Age at marriage, economic status and other factors probably complicate the problem.
  4. Pearson, K., "On the Correlation of Fertility with Homogamy," Proc. Roy. Soc. Lond., Vol. 66, pp. 28-32; also Biometrika, Vol. 2, pp. 373-376.
  5. Homogamy means merely the mating of physically or psychically similar individuals. Sameness of stock, endogamy, is of course not implied.