Speke had earlier proven his mettle by trekking through the mountains of Tibet, but Burton regarded him as inferior as he did not speak any Arabic or African languages. Despite his fascination with non-European cultures, some have portrayed Burton as an unabashed imperialist convinced of the historical and intellectual superiority of the white race, citing his involvement in the Anthropological Society, an organization that established a doctrine of scientific racism. Speke appears to have been kinder and less intrusive to the Africans they encountered, and reportedly fell in love with an African woman on a future expedition.