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Todd Risley

Todd Risley

Todd R. Risley was a professor of psychology at the University of Alaska and former professor of human development and senior scientist of the Bureau of Child Research at the University of Kansas. He is the co-author, with Betty Hart, of the  book Meaningful Differences in the Everyday Experience of Young American Children.

Watch the full Reading Rockets webcast, From Babbling to Books: Building Pre-Reading Skills, featuring Risley, Sharon Landesman Ramey, and Julie Washington discussing research-based strategies for developing language and pre-reading skills in young children.


Todd R. Risley, a founding father of applied behavior analysis died on November 2, 2007, at his home at the foot of Risley Mountain in his beloved Alaska.

Risley received his undergraduate degree from Lewis and Clark College in Oregon and completed his doctorate at the University of Washington in 1966. He was a principal faculty member in the Department of Human Development and Family Life at the University of Kansas during the early years of the field of ABA, and in recent years served as Professor Emeritus at the University of Alaska in Anchorage.

Known internationally for his research and writings, Risley authored more than 100 professional articles and five books which have been widely cited and reprinted. One of these publications was nominated for a Pulitzer Prize. Another of his notable works, Meaningful Differences in the Everyday Experience of Young American Children (coauthored with Betty Hart), discusses how children acquire language. In that seminal book, Hart and Risley show that an important indicator of a child’s competence in speech, vocabulary usage, is directly related to the amount of speech that parents have with their children. The book continues to be frequently referenced and to generate much discussion.

Books by this author