Morton believed that cranial capacity determined intellectual ability, and he used his craniometric evidence in conjunction with his analysis of anthropological literature then available to argue in favor of a racial hierarchy which put Caucasians on the top rung and Africans on the bottom. His skull measurements (by volume) then came to serve as "evidence" for racial stereotypes. He described the Caucasian as "distinguished by the facility with which it attains the highest intellectual endowments"; Native Americans were described as "averse to cultivation, and slow in acquiring knowledge; restless, revengeful, and fond of war, and wholly destitute of maritime adventure" and the Africans he described as "joyous, flexible, and indolent; while the many nations which compose this race present a singular diversity of intellectual character, of which the far extreme is the lowest grade of humanity".