Starfleet Psychological Division
Starfleet Psychological Division was an agency within theUnited Federation of PlanetsStarfleet which was responsible for reporting on the mental impact on a crew duringstarship travel. They were well aware that a crew of only three for a mission of twenty to twenty eight months had to be carefully chosen for compatability.
The Psych Division undertook a momumental task in analyzing personal traits and studying how they effected shipboard interactions in small groups under such remote circumstances. While Starfleet was waiting for the Psych Division's final accounting of how to select such specialized crews, they assembled some crews together, regardless of compatibility, justified by the need to keep Starfleet operating normally. (TOS -Worlds Apartnovel:How Much for Just the Planet?)

