Intraindividual variability (IIV) in cognitive speed, or moment-to-moment changes in ability, is a developmental phenomenon indicative of neurological integrity that increases gradually across adulthood. Past research has shown that IIV negatively covaries with cognitive performance, in which higher IIV at one occasion is associated with poorer…

Only a longitudinal study, in which retrospective reports can be verified against data collected earlier, can determine what topics tend to be reported accurately and whether certain types of individuals are more likely to be accurate reporters. A representative group of adults who became parents 50 years ago are now part of the oldest and longest…

Only a longitudinal study, in which retrospective reports can be verified against data collected earlier, can determine what topics tend to be reported accurately and whether certain types of individuals are more likely to be accurate reporters. A representative group of adults who became parents 50 years ago are now part of the oldest and longest…

Summarizes the conduct and results of the Seattle Longitudinal Study, an investigation that has assessed mental abilities in more than 5,000 adults and has followed some for as long as 35 years. Integrative findings are presented on age changes, cohort differences, factor structure, individual differences, and interventions. (SLD)