It will be evident at once that where individuals of the same race and hence the same temperament are associated, the temperamental interests will tend to reinforce one another, and the attention of members of the group will be more completely focused upon the specific objects and values that correspond to the racial temperament. In this way racial qualities become the basis for nationalities, a nationalistic group being merely a cultural and eventually a political society founded on the basis of racial inheritances. On the other hand, when racial segregation is broken up and members of a racial group are dispersed and isolated, the opposite effect will take place. This explains the phenomena which have frequently been the subject of comment and observation, that the racial characteristics manifest themselves in an extraordinary way in large homogeneous gatherings. The contrast between a mass meeting of one race and a similar meeting of another is particularly striking. Under such circumstances characteristic racial and temperamental differences appear that would otherwise pass entirely unnoticed. When the physical unity of a group is perpetuated by the succession of parents and children, the racial temperament, including fundamental attitudes and values which rest on it, are preserved intact. When however, society grows and is perpetuated by immigration and adaptation, there ensues, as a result of miscegenation, a breaking up of the complex of the biologically inherited qualities which constitute the temperament of the race. This again initiates changes in the mores, traditions and eventually in the institutions of the community. The changes which proceed from modification in the racial temperament will, however, modify but slightly the external forms of the social traditions but they will be likely to change profoundly their content and meaning. Of course, other factors, individual competition, the formation of classes, and especially the increase of communication, all cooeperate to complicate the whole situation and to modify the effects which would be produced by racial factors working in isolation. All these factors must be eventually taken account of, however, in any satisfactory scheme of dealing with the problem of Americanization by education. This is, however, a matter for more complete analysis and further investigation. ROBERT E. PARK FOOTNOTES: [1] This address was delivered before the American Sociological Society convened in annual session at Richmond in 1918. [2] "The City: Suggestions for the Investigation of Human Behavior in the City Environment," _American Journal of Sociology_, V, 44, March, 1915, p. 589. [3] Rivers, "Ethnological Analysis of Cultures," _Nature_, Vol. I, 87, 1911. [4] W. J. McGee, _Piratical Acculturation_.