It also included fucked up behavioral conditioning experiments (or at least these were adjacent to mkultra) to test people’s response under interrogation.
One notable case from this was Ted Kaczynski, the Unabomber, who was subjected to extreme duress without informed consent. The study used students essays and interviews to then subject them to “vehement, sweeping, and personally abusive” interrogations designed to “break” them.
Note that Kaczynski was by many reports brilliant at mathematics and as a result of this was accepted to Harvard at 15 years old, starting at 16. The study happened in his second year, sometime when he would’ve been 16-17. Further, while there are reports that while he was very academically gifted he was fairly emotionally unprepared for college though tbf most of these came to light after his infamy.
https://behavior.org/unabomer-extreme-reaction-behavior-modification/
https://www.history.com/articles/what-happened-to-the-unabomber-at-harvard
Personality, in short, is consistent patterns of behavior that exist across time and context. Someone “extroverted” will consistently explore new environments, while someone shy will avoid them
There have been studies that show insects display some aspects of personality