[176] It is noteworthy that in the _Round-About_, already referred to, although no man expresses a desire to meet a short woman, when he refers to announcements by women as being such as would be likely to suit him, the persons thus pointed out are in a notable proportion short.
[177] It has been discussed by F.J. Debret, _La Selection Naturelle dans l'espèce humaine_ (Thèse de Paris), 1901. Debret regards it as due to natural selection.
[178] "Hérédité de la Couleur des Yeux dans l'espèce humaine," _Archives des Sciences physiques et naturelles_, sér. iii, vol. xii, 1884, p. 109.
[180] F. Galton, _Natural Inheritance_, p. 85. It may be remarked that while Galton's tables on page 206 show a slight excess of disparity as regards sexual selection in stature, in regard to eye color they anticipate Karl Pearson's more extensive data and in marriages of disparity show a decided deficiency of observed over chance results. In _English Men of Science_ (pp. 28-33), also, Galton found that among the parents parity decidedly prevailed over disparity (78 to 31) alike as regards temperament, hair color, and eye color.
[181] Karl Pearson, _Phil. Trans. Royal Society_, vol. clxxxvii, p. 273, and vol. cxcv, p. 113; _Proceedings of the Royal Society_, vol. lxvi, p. 28; _Grammar of Science_, second edition, 1900, pp. 425 _et seq._; _Biometrika_, November, 1903. The last-named periodical also contains a study on "Assortative Mating in Man," bringing forward evidence to show that, apart from environmental influence, "length of life is a character which is subject to selection;" that is to say, the long-lived tend to marry the long-lived, and the short-lived to marry the short-lived.
[182] For a summary of the evidence on this point see Havelock Ellis, _Man and Woman_, fourth edition, 1904, pp. 256-264.
[183] "The Comparative Abilities of the Fair and the Dark," _Monthly Review_, August, 1901.
[184] The fact that even in Europe the abhorrence to incest is not always strongly felt is brought out by Bloch, _Beiträge zur Ætiologie der Psychopathia Sexualis_, Teil II, pp. 263 et seq.
[185] Westermarck, _History of Marriage_, Chapters XIV and XV.
[186] Crawley (_The Mystic Rose_, p. 446) has pointed out that it is not legitimate to assume the possibility of an "instinct" of this character; instinct has "nothing in its character but a response of function to environment."