Warp drives, maybe not, but multigenerational space travel at slow speeds might actually require a certain amount of social cohesion and cooperative tendency, a

Warp drives, maybe not, but multigenerational space travel at slow speeds might actually require a certain amount of social cohesion and cooperative tendency, as well as a pioneer's ambitious personality--the rigors of the journey combined with those of establishing civilization on a planet without any humans to enslave and manipulate will add up to significant selective pressure on settlers.