Before Ted Kaczynski became the infamous Unabomber, he was a gifted, 16-year-old student at Harvard University. Kaczynski may have been precocious in his intellect, but he was also impressionably young—and it was at Harvard where Kaczynski would be recruited to take part in a three-year-long psychological experiment.

After investigators discovered in 1996 that the former youthful genius became a reclusive murderer responsible for a horrific series of bombings that killed three people and injured 23, they took an interest in the three-year experiment that Kaczynski later described as “the worst experience" of his life.

Kaczynski entered Harvard in 1958 and, one year later, was tapped by psychologist Henry A. Murray to take part in a study exploring the effects of stress on the human psyche—a popular area of research during the Cold War. The experiment enlisted 22 Harvard students to write a detailed essay in which they summarized their worldview and personal philosophy. Then the harsh aspects of the experiment began.

After submitting their essays, each of the students was seated in front of bright lights, wired to electrodes and subjected to what Murray himself described as “vehement, sweeping, and personally abusive” interrogations, during which members of his research team would attack the student subjects’ ideals and beliefs, as gleaned from their essays. The goal was to assess the value of interrogation techniques used by law enforcement and national security agents in the field.

“It’s clearly unethical and violates all of the main ethical principles for psychologists as promulgated by the American Psychological Association,” says Nigel Barber, Ph.D., an evolutionary psychologist who writes a regular column called “The Human Beast: Why We Do What We Do” for Psychology Today and is the author of several books on human behavior.

“Subjects were incompletely informed about the nature of the experiment [and] were tricked, or coerced, into remaining in the experiment. Given that the procedures were designed to ‘break’ enemy agents and render them so damaged that they would be operationally useless, it is reasonable to expect that they would have the same consequences for vulnerable young people who did not have specialized training to resist interrogation.”

Murray is still considered an important researcher and clinician in the field of psychology, and his personality assessments remain a fundamental part of psychological evaluations to this day.

However, his legacy (he passed away in 1988) has been tarnished somewhat by this study, in which Kaczynski was one of the subjects. In fact, the study drew a lot of negative attention in the aftermath of the Unabomber’s arrest as details of his early life emerged. (Kaczynski was found dead, reportedly by suicide, in his cell on June 10, 2023.)

Experiments such as Murray’s almost certainly wouldn’t be allowed today under current ethical standards for research—but at the time, it wasn't considered a violation of any code of research conduct.

According to Barber, researchers at the time of Murray’s experiment were governed by the Nuremberg Code of research ethics—established at the Nuremberg Trials shortly after the end of World War II—which, though not legally binding, still serves as the basis for ethical standards in research today.

After several infamous cases of human experiments gone awry—most notably, Stanley Milgram’s study in which participants were coerced into believing that they had administered fatal electrocutions to others who had failed to follow their instructions—the American Psychological Association (APA) in 1982 published detailed guidelines on how research should be conducted called “Ethical Principles in the Conduct of Research with Human Subjects.”

Today, “all university research, including experiments on humans, must pass scrutiny of an Institutional Review Board or Ethical Review Panel,” Barber explains. “These [committees] pore over procedural details and may reverse an approval if ethical problems surface in the course of the research.”

Although it’s now the widely held view that experiments like Murray’s are unethical and may cause harm to those who participate in them, there’s no direct correlation between Kaczynski’s involvement in the study and his actions later in life as the Unabomber.

“I think it is reasonable to identify this episode as approximately the time around which Kaczynski’s life began to unravel, [but] this might be coincidental,” notes Barber.

Barber points out that Kaczynski was later diagnosed with schizophrenia and that young adulthood is often the time when this illness strikes. But he was subsequently hired as an academic mathematician and, Barber says, "proved an able researcher."

“The Harvard experiment was stressful and stress aggravates the symptoms of schizophrenia. Otherwise, it would be a mistake to exaggerate the importance of this experience, or to see it as a major determinant of his anti-science and anti-technology political views," Barber says. "It was just one more personal grudge that he could fit into a paranoid narrative about how the world worked in general, and for him in particular.”