As a sophomore, Kaczynski participated in a study described by author Alston Chase as a "purposely brutalizing psychological experiment" led by Harvard psychologist Henry Murray.
Subjects were told they would be debating personal philosophy with a fellow student, and were asked to write essays detailing their personal beliefs and aspirations. The essays were turned over to an anonymous attorney, who in a later session would confront and belittle the subject – making "vehement, sweeping, and personally abusive" attacks – using the content of the essays as ammunition, while electrodes monitored the subject's physiological reactions.
These encounters were filmed, and subjects' expressions of anger and rage were later played back to them repeatedly.
The experiment lasted three years, with someone verbally abusing and humiliating Kaczynski each week.
Kaczynski spent 200 hours as part of the study.
Kaczynski's lawyers later attributed his hostility towards mind control techniques to his participation in Murray's study.
Some sources have suggested that Murray's experiments were part of Project MK-Ultra, the Central Intelligence Agency's research into mind control.
Chase and others have also suggested that this experience may have motivated Kaczynski's criminal activities.