Stanford psychologist behind the controversial ‘Stanford Prison Experiment’ dies at 91

SAN FRANCISCO (AP) — Philip G. Zimbardo, the psychologist behind the controversial “Stanford Prison Experiment” that was intended to examine the psychological experiences of imprisonment, has died. He was 91.

Stanford University announced Friday that Zimbardo died Oct. 14 at his home in San Francisco. A cause of death was not provided.

In the 1971 prison study, Zimbardo, then 38, and a team of graduate students recruited college-aged males to spend two weeks in a mock prison in the basement of a building on the Stanford campus.

In a 2016 interview with the Bay Area News Group, Zimbardo said the subjects were 24 psychologically healthy male college students, were paid $15 a day to participate and were randomly assigned to play prisoners or guards.

Zimbardo outfitted the guards in khaki uniforms and mirrored sunglasses and told them to create an atmosphere in which the prisoners felt “powerless.” The experiment took place in Jordan Hall’s basement where offices, vacated for the summer, were transformed into the “Stanford County Prison.”

The study was ended after six days as the students playing guards became psychologically abusive and those playing prisoners became anxious, emotionally depressed and enraged, according to the Stanford statement.

Zimbardo was criticized for taking the role of superintendent – becoming an active participant in the study and no longer a neutral observer.

“The outcome of our study was shocking and unexpected,” Zimbardo would later co-write with one of the graduate students who was part of the project.

For years, critics, including other psychologists and some participants, continued to question the validity of the study, which Zimbardo insisted demonstrated that the dynamics of certain situations can lead ordinary people to behave badly.

The experiment is now used in psychology classes to study the psychology of evil and the ethics of psychological research with human subjects, Stanford said.

“Zimbardo first received national attention for his 1969 study that examined the causes of vandalism,” the university said. “He believed that anonymity and a lack of community could lead to antisocial behavior.”

His research also included persuasion, hypnosis, cults, shyness (he founded the Stanford Shyness Clinic), time perspective, altruism and compassion, according to Stanford.

Zimbardo is survived by his wife, Christina Maslach Zimbardo, three children and four grandchildren.