Hoffman worked at the New York Psychiatric Institute, affiliated with Columbia University, when he was 21. "It was a great experience for me," he said. "All my life I had wanted to get inside a prison or a mental hospital. . . . I wanted to get inside where behavior, human behavior, was so exposed. All the things the rest of us were feeling and stopping up were coming out of these people." He used that experience to help him develop the character of Raymond Babbitt, a high-functioning autistic savant, yet a person who critic David Denby described as "a strangely shuttered genius." Hoffman created certain character traits for Raymond. Denby noted: "Hoffman, looking suddenly older and smaller, has developed a small shuffling walk for Raymond, with shoulder bent. His eyes don't make contact with anyone else's, and he flattens his voice to a dry nasal bark."