B. F. Skinner (1909-1990) was a prominent professor of psychology at Harvard (1958-1974) and a founder of Operant and Behavioral Psychology.
When the American POWs returned from captivity in Vietnam, military authorities noticed there were no amputees. At the time, this puzzled the experts. With over 2000 men in captivity, one would expect at least a few amputees. But in light of what is known about the Soviet human experimental program, it now makes a lot more sense. Most likely, these men were used either for military experiments or for training young surgeons. As in North Korea, once the procedures were completed the "experimental subjects" were killed and their bodies incinerated.
In the early 1950s, U.S. intelligence concluded that the KGB, Soviet intelligence, was working hard to develop "mind control" and behavior modification drugs. Supporting evidence included the public "confessions" of numerous high-ranking communist officials, the high-profile trial in Hungary of Josef Cardinal Mindszenty, who appeared to have been drugged as he confessed to treasonous crimes, and the unusual behavior of American POWs during the Korean War.
Sometimes in history, events of enormous brutality involving large numbers of people can be successfully kept secret from the general public for long periods of time. For example, in the case of Operation Keelhaul following World War II, hundreds of thousands of men, women and children were forcibly sent back to the Soviet Union by the United States and British governments to a certain death or enslavement in labor camps. It wasn't until Julius Epstein finally exposed this event that the world learned of this atrocity.