ALTHOUGH MANY studies1 of the stress effects of perceptual isolation have been reported, only a few of these2-4 have used control groups which would enable one to separate the effects of perceptual isolation from those due to confinement and social isolation. Despite the large variance obtained between subjects in such studies, only Leiderman5 has attempted to use the subject as his own control.
Likewise, personality measures have been correlated with endurance (time) in isolation and various types of isolation responses,1 but it has been impossible to determine whether these personality variables are specifically related to reactions to perceptual isolation, or to the broader situation of social isolation and confinement. Furthermore, few of the reported personality relationships have been replicated.
Among the response variables that have been employed, only three studies to date have attempted to assess endocrine function in relation