Assortative mating in somatic traits and its consequences

The problem of assortative mating embraces non-random mating of spouses. However, it is often discussed together with its consequences, which results from the fact that when we study similarities between spouses at various stages of their acquaintance and/or living together we must take into consideration not only the criteria of mating but also the consequences like, for instance, "resembling" (synchronous changes in husband and wife) and perhaps compensation of one's traits. This problem has not been sufficiently examined so far and further studies are necessary (Wolaánski 1970c, Nikityuk and Filipov 1975, Kasprzak and Wolański 1977, Thiessen and Gregg 1980, James 1989). The problem of assortative mating involves both the reasons principally genetic-evolutionary problems (Pearson 1896, Wolański and Siniarska 1983, 1984)--and the consequences as well, like, for instance homosis, that is transmitting to the offspring similar genes from defined loci, and heterosis, that is transmitting the different genes. Thus problem constitutes genetic foundations of auxology. Also an ecological problem is added, namely a synchronous resemble changes of spouses connected with similar living conditions and life style. Assortative mating seems to be a simple problem but in fact it is a scientific problem in which genetic, ecological and auxological approaches are combined. Below we will discuss assortative mating from these angles with reference to some anthropological traits. As a matter of fact, assortative mating is concerned with such a fundamental problem in the biomedical and social sciences as development the traits of the offspring (organism level) and of the whole future generations (population level). This is a problem of great importance by no means theoretical only. In our studies the main emphasis has been on spouses similarities in the morphological, physiological and psychomotor traits and also on some changes in the successive generations (which was connected with the lasting of marriage before the moment of investigations). The variations of traits of the populations were also taken into consideration as well as the effects of assortative mating of spouses on the development of their children. The above mentioned problems will constitute the contents of the present chapter. Studies on assortative mating have had a long tradition in Poland and most probably are one of the earliest in the world, apart from those conducted by Pearson (1896) in Great Britain and the Anonymous ones from 1903. This pertains mostly to B. Rosiński's (1923, 1925, 1926, 1929) investigations conducted in Poland in 1918 and on Polish immigrants to Brazil in 1931 and USA in 1929-30 (Stołyhwo 1931, Rosiński 1934).