In 1966, a computer scientist at MIT named Joseph Weizenbaum built a small program that would haunt him for the rest of his life. He called it ELIZA, after Eliza Doolittle, the flower girl in Pygmalion who is taught to imitate the speech of a higher class.

The program ran a script he named DOCTOR, and that script imitated a Rogerian psychotherapist, the kind of therapist who reflects your words back at you rather than offering opinions.