In 1971, he published the book "The Insect Societies" about the biology of social insects like ants, bees, wasps and termites. In 1973, Wilson was appointed 'Curator of Insects' at the Museum of Comparative Zoology. In 1975, he published the book "" applying his theories of insect behavior to vertebrates, and in the last chapter, humans. He speculated that evolved and inherited tendencies were responsible for hierarchical social organisation among humans. In 1978 he published "On Human Nature", which dealt with the role of biology in the evolution of human culture and won a Pulitzer Prize for General Nonfiction.