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". Morton's followers, particularly Josiah C. Nott and George Gliddon in their monumental tribute to Morton's work, Types of Mankind (1854), carried Morton's ideas further and backed up his findings which supported the notion of polygenism – the premise that the different races were separately created by God. The publication of Charles Darwin's On the Origin of Species in 1859 changed the nature of the scholarly debate. Morton amassed over 1,000 human skulls. Some of the skulls that Morton collected and measured include those of enslaved people. Morton amassed his collection of human skulls when he worked at the Academy of Natural Sciences. The collection was transferred to the University of Pennsylvania Museum of Archaeology and Anthropology in 1966. In 2021, the University of Pennsylvania Museum apologized for the unethical collection and promised to repatriate the remains of the people whose skulls were collected by Morton. The museum has promised to provide burials for 13 skulls of Black Philadelphians. Allegations of bias in data collection and interpretation In a 1978 paper and later in The Mismeasure of Man (1981), Stephen Jay Gould asserted that Morton had, perhaps because of an unconscious bias, selectively reported data, manipulated sample compositions, made analytical errors, and mismeasured skulls in order to support his prejudicial views on intelligence differences between different populations. Gould's book became widely read and Morton came to be considered one of the most prominent cases of the effects of unconscious bias in data collection, and as one of the main figures in the early history of scientific racism. Subsequently, two separate studies of Morton's data and methods, one conducted in 1988 and the other in 2011, argued that Gould had overstated or misrepresented the case, and that Morton's measurements were essentially correct. In the latter study, entitled "The Mismeasure of Science: Stephen Jay Gould versus Samuel George Morton on Skulls and Bias" and authored by six anthropologists, it