A psychological profile was a scientific analysis of a person's mental health and ability. Such profiles were routinely kept on applicants to and members of Starfleet in the 23rd and 24th century. In 2268, when Captain Kirk was showing signs of increased tension and emotional stress, he repeatedly resisted Doctor McCoy's attempts to run a psychological profile on him. Unbeknownst to McCoy, Kirk was working under Federation orders to steal a Romulan cloaking device. (TOS: "The Enterprise Incident" )