Leon Kamin

Leon J. Kamin (1927 to 2017) was an American psychologist known for his contributions to learning theory and for his critique of heritability estimates of IQ. He studied under Richard Solomon at Harvard, and in 1969 described the blocking effect, in which an animal already conditioned to one signal fails to learn a second signal presented alongside it. After refusing to name names before a Senate committee in the 1950s he worked in Canada, then chaired the psychology departments at Princeton and Northeastern. His investigation of Cyril Burt's twin data led to The Science and Politics of IQ (1974), and he co-wrote the controversial Not in Our Genes (1984).