LONDON--Buried in a sleepy corner of the Harvard campus, somewhere in the nation's largest collection of psychological data, lies a slim folder whose sealed contents might help explain what drove the Unabomber to kill.

Theodore J. Kaczynski '62, who was arrested in 1996 after killing three and injuring 16 in a string of mail bombings spread over 20 years, participated in an intensive, sometimes brutal, three-year psychological study while a Harvard undergraduate.

The results of the study, directed by famed psychologist Henry A. Murray, are now housed at the Radcliffe Institute research center named in Murray's honor. But though the records may shed light on Kaczynski's psychological history, the Murray Center has locked the file up for good.

"We have a very strong policy of maintaining the confidentiality of people who participate in studies archived here," Murray Center Director Annemette Sorensen said. "This particular file has been permanently removed, with the reason being that we cannot protect its confidentiality anymore."

Kaczynski's code name in the study--"Lawful"--has become widely known to journalists and researchers, and Sorensen said that because the Murray Center promises to maintain the confidentiality of study participants, there are no circumstances under which Kaczynski's file could be opened.

"It would undermine everything we try to do here, and it would really mean that we would begin to lose control over those important principles," she said.

Author Alston Chase suggested in a recent Atlantic Monthly article that Kaczynski's participation in the Murray study might have pushed him over the edge from an isolated student to a revolutionary against science and society. Kaczynski's bomb attacks often targeted science professors and airline executives.

Called "Multiform Assessments of Personality Development Among Gifted College Men," the study consumed hundreds of hours of participants' time over three years.

In one part of the experiment, subjects were pressured to respond to questions asked under extreme duress, with bright lights and cameras pointed at them and electrodes attached to their bodies.

Dr. Ross Neissuler, who also took part in the study, said that participants also took the Thematic Apperception Test, a psychological test that Murray himself developed.

The experiences left some participants scarred for life.

Chase cites several other participants in the study who were quite disturbed by the experience, and remembered years later how angry, frightened and violated they felt. Chase suggests that feelings of this kind might have driven Kaczynski to lash out against society.

Kaczynski, according to Chase, was already mentally unstable before entering Harvard, and his 8 Prescott Street residence during his first year only served to isolate him further from his fellow students. Murray's study, Chase speculates, took that isolation even further, pushing the psychological limits of the young participants in nearly every way possible.

Murray, a former colonel in the U.S. Army and an agent for the Office of Strategic Services (OSS), made his mark on the government during World War II before returning to Harvard to continue his work as a professor.

During his time at the OSS, according to his former colleagues, Murray was obsessed with mind control and used LSD, among other drugs, attempting to determine how to brainwash subjects. Murray presented his findings after taking LSD at an international conference in Copenhagen.

And some believe that Murray's Harvard studies--which, as Neissuler recalled, "never seemed to have any particular application"--were a continuation of his work at the OSS.

Edwin Schneidman, a former Murray colleague, who worked with Murray while at Harvard, said that Murray's interest in mind-altering drugs continued after the war. "He did do research involving LSD while he was at Harvard," Schneidman said.

Some experts on the Kaczynski case, including The United States of America vs. Theodore John Kaczynski author Michael Mello, have speculated that LSD tests may also have been a part of the study Kaczysnki took part in. But Kacyznski himself does not recall taking the drug, and there is no evidence that LSD was part of the experiment.