T HE CAUSES of intergroup tension and conflict in our society are manifold. Most of those who have given close attention to the phenomena considered in this book, and who are not apologists for one specific theory of social behavior, are aware that no one factor is the determining cause of prejudice or its manifestations in discrimination. The phenomena to be explained are manifested in such diverse ways, and the influences on them are sometimes so complicated and subtle, that we do not yet know all the factors behind prejudice and discrimination. The following analysis is therefore tentative, and consists of a number of specific hypotheses for further testing. In each case there is a good deal of evidence in support of the proposition given, but in no case is there adequate proof. Thus, while we cannot be satisfied with the following theories, they are far more satisfactory than the popular attempts at explanation that are known to be wrong.
One of the incorrect popular theories is that prejudice is based upon biological racial differences. It is assumed in this theory that people are born into different biological races that are endowed with different natural capacities. Since one race is considered to be inferior to another, it is thought desirable that the inferior race be subjected to the control of the superior. Above all, this theory holds, there must be no biological amalgamation among the races, for otherwise the superior race would degenerate as it combined its heredity with that of the inferior. Our scientists know that there are different races, but they also know that there is no basis whatsoever for assuming that there is any difference in average biological capacity, nor is there any basis for the belief that racial intermixture is harmful in any way. Certainly there is no scientific or____________________