Darwin also inspires future applications of his theory by suggesting that progress is inherent to the process of natural selection, and that progress always results in greater good for the inhabitants of the natural world. Darwin argues that natural selection constantly makes species more complex and therefore closer to being perfectly adapted to their environments. At the same time, Darwin’s theory of development implies that hierarchies exist among species—that those lower on the “chain of development” are less advanced, and therefore less likely to survive, than those higher up on the chain. Years later, Social Darwinists would incorrectly apply this concept to human society, both in regard to race and class, arguing that poor people and criminals were lower, degenerate human beings. By calling the species of Great Britain (his nation) “the best” in the world, Darwin himself reveals the kind of bias that the Social Darwinists would expand on. Darwin could have never foreseen the Social Darwinist movement or predicted that his theories would be used in racist ways, but these negative applications remain a historical legacy of his theory of natural selection.