Cohort-sequential analyses were conducted on measures from the Primary Mental Abilities Test and the Test of Behavioral Rigidity for 2,151 participants at the first testing and 723 individuals at the retesting 7 years later. Data were examined for 7-year age intervals from 25 to 81 years and cohort intervals from 1889 to 1938. (Author/JMB)

The results of this study highlight the cognitive intellectual aspect of the speed of behavior. These findings supplement Hunt's studies of the relationships between speed of cognitive processing and performance of young adults on conventional tests, and emphasize the importance of cognitive speed for subsequent intellectual development. (Author)

This report reviews a theoretically inspired empirical investigation of individual differences in knowledge, abilities, and nonability traits as part of an ongoing effort to better understand adult intellectual development and to develop more accurate measures of adult intelligence. Twenty Knowledge Scales were constructed, drawing on…