Rigidity, as it relates to aging, refers to motor/cognitive, personality/perceptual, and psychomotor functioning. To investigate the relationship of rigidity to intelligence and educational level in younger and older adults, and of rigidity to age and sex, 48 young adults (25 male, 23 female), with a mean age of 23, and 45 older adults (21 male, 24 female), with a mean age of 65, completed the Test of Behavioral Rigidity and the Quick Test. An analysis of the results showed that intelligence and educational level were significantly correlated with rigidity in the older group but not in the younger group. Contrary to expectations, younger individuals were found to be more rigid, except in psychomotor speed, than older adults. Males were more rigid than females in both age groups. (Author/BL)