Timeline:
1960s
Colby begins using computer science in psychiatry at Stanford University, developing computational models for mental processes and critiquing psychoanalysis.
1966
Joseph Weizenbaum releases ELIZA, which inspires Colby to pursue AI models for psychiatric simulation.
1971
Colby and collaborators publish Artificial Paranoia in Artificial Intelligence, introducing the PARRY model.
1972
PARRY is implemented in MLISP on a PDP-10 at Stanford AI Lab. It undergoes a Turing-like indistinguishability test in which psychiatrists fail to reliably differentiate it from human patients. That same year, PARRY and ELIZA communicate over ARPANET, marking an early instance of machine-to-machine dialogue.
1974
Colby publishes Ten Criticisms of PARRY and the Stanford AI Memo AIM-244, addressing PARRY’s limitations and technical features.
Late 1970s–1980s
PARRY appears in academic discourse, including Colby’s 1981 Modeling a Paranoid Mind. Colby expands his work to include AI systems for depression and aphasia, applying insights from the PARRY project.
1990s
PARRY remains a key reference in AI and computational psychiatry. In 1999, Colby reflects on its legacy in Machine Conversations.
2001
Kenneth M. Colby dies. PARRY continues to be studied as a seminal contribution to dialog systems, psychiatric modeling, and the ethics of AI in mental health.
Legacy
PARRY is recognized as the first AI chatbot to pass a domain-specific Turing Test and is foundational in the fields of robopsychology, dialog systems, and computational psychiatry.
Wikipedia:
See also:
The story of the PARRY chatbot begins in the 1960s with Kenneth M. Colby, a psychiatrist at Stanford University who became disillusioned with psychoanalysis due to its lack of empirical rigor. Influenced by the emerging field of artificial intelligence and inspired by Joseph Weizenbaum’s 1966 program ELIZA, Colby set out to create a more psychologically grounded chatbot that could simulate mental illness—specifically, paranoid schizophrenia. Unlike ELIZA, which relied on simple pattern matching to mimic a nondirective therapist, Colby wanted to build a system with internal models of belief, emotion, and intention.
In 1971, Colby and his colleagues introduced PARRY in a paper titled Artificial Paranoia, describing it as a rule-based dialogue system that simulated the cognitive distortions typical of paranoia. PARRY was implemented in 1972 using the MLISP language on a PDP-10 computer. It incorporated variables to represent affective and belief states and used these to produce coherent, psychologically plausible responses. That same year, it was subjected to a Turing-like test in which psychiatrists conversed with both PARRY and real patients via teletype; they failed to reliably distinguish between the two. Also in 1972, PARRY and ELIZA were linked over ARPANET and engaged in what became one of the earliest machine-to-machine conversations.
In 1974, Colby published Ten Criticisms of PARRY and the Stanford AI Memo AIM-244, which detailed the model’s technical framework and addressed critiques. Throughout the late 1970s and into the 1980s, PARRY was referenced in scholarly work, including Colby’s own Modeling a Paranoid Mind (1981), and it influenced applications in depression treatment and aphasia support.
By the 1990s, PARRY was recognized as a foundational AI dialogue system. In 1999, Colby reflected on its impact in the book Machine Conversations, noting its lasting influence on psychiatry and AI. Colby died in 2001, but PARRY remains a pivotal example in the history of AI, notable for being the first program to pass a domain-specific Turing Test and for its role in the development of computational psychiatry. Today, PARRY is preserved in historical archives and continues to be studied as a milestone in both artificial intelligence and mental health research.