But if differences in racial attainments are due to differences in environment, it might be said that this itself is testimony to the superiority of the race that has the more complex and exacting environment. This is not by any means clearly the case. The "culture" or civilization which a race exhibits is a very uncertain index of its gifts or its capacities. The culture found in a race is, it may be said without exaggeration, largely a matter of accident or circumstance rather than of heredity. Some of the environmental causes for differences in culture may he explicitly noted. Any modern culture is the result of interminglings of many different cross-streams and cross-borrowings. Races that have long been isolated as, for example the African negroes, have no possibility of picking up all the acquisitions to which races that intermingle have access. Progress in the developments of arts, sciences, and institutions depends on fortunate individual variations. The smaller the race the less the number of variations possible, including those on the side of what we call genius. Again fortunate variations depend not so much on the general average intellectual capacities of the race as on its variability. So one race may possess a relative superiority of achievement because of its high variability, just as, as we have already pointed out, the greater preeminence of the male sex with regard to intellectual accomplishment is due to the greater number of variations both above and below the norm which it displays. The reasons for variability are again, according to Professor Boas, largely environmental. "We have seen, when a people is descended from a small uniform group, that then its variability will decrease; while on the other hand, when a group has a much-varied origin or when the ancestors belong to entirely distinct types the variability may be considerably increased."[1] [Footnote 1: Boas; _loc. cit._, p. 93.] Again a race may be placed in such geographical conditions that a fortuitous variation on the part of one individual may prove of enormous value in the development of its civilization. Or fortunate geographical conditions may stimulate types of activity that lie dormant, although possible, among other races. Thus by some investigators the flexibility and emancipation of the Greek genius were attributed to their access to the sea and their constant intermingling with other cultures, especially the Egyptian. On the subject of the fundamental equality of races despite their seeming disparity, as that at present, let us say, between whites and negroes, Professor Boas writes: