Sidney Bijou, the psychologist who developed behaviorist principles into a therapeutic system for children with a range of disorders, died on June 11 at the age of 100. There is an extensive obituary in the New York Times. Bijou worked with radical behaviorist B. F. Skinner in the 1940s, and he came to believe that reinforcing desirable behavior with praise or a hug or just attention would help children who were not responsive to traditional punishments or therapies. Bad behavior was ignored or, if particularly dispurtive, resulted in a short “time out,” which has since become a culturally pervasive technique. Bijou started using his new approach with defiant children, but as the system grew in popularity, it came to be a standard system for helping autistic and attention-deficit children as well, under the name of applied behavior analaysis, or ABA.