We examined whether externalizing problems showed construct validity invariance over time by examining the convergent validity of externalizing and its discriminant validity with respect to internalizing problems. Ratings of externalizing problems and internalizing problems were divided into 3 different blocks according to the primary raters within the era: block 1 = ages 5–13 (parent- and teacher-report), block 2 = ages 14–17 (parent- and self-report), block 3 = ages 19–27 (self- and peer-report). POM-rescaled ratings were averaged across years within a given block. We tested whether externalizing problems predicted later externalizing problems more strongly than later internalizing problems.
