20 volunteers from each of the 3 major mental health professions made clinical judgments of the presence or absence of “rigidity” in 16 case histories. The histories contained all possible combinations of 4 literature-identified aspects of rigidity. The results indicate that rigidity is considered present when an individual shows 2 or more of the following: failure to adapt to changing situations, involuntary repetition of responses, emotional-intellectual suppression. If he experiences stress, anxiety, or insecurity, rigidity is contra-indicated. Considering the differences between such clinical views of rigidity and those incorporated in most laboratory research, it is suggested that attempts be made to demonstrate predictive validity of the clinical concept.