Stability of externalizing symptoms from kindergarten to first grade and factors related to instability

This article examines the frequency and stability of externalizing symptoms in a sample of 325 5-year-olds. Parent and teacher ratings, teacher nominations, parent-child interaction, and child measures were obtained. Using cutoff scores on teacher ratings, an average of 20% of the children were rated as having moderate externalizing problems in kindergarten and first grade. For both boys and girls, parent-teacher stability correlations ranged from .34–.45, and kindergarten teacher ratings from November and April correlated at .76. Instability in externalizing symptoms from kindergarten to first grade was related to a number of concurrent and previously assessed factors. For girls these included learning problems, shy-anxious behavior, mother-child interaction measures, and cognitive ability. Factors related to instability for boys included learning problems, social skills, cognitive ability, and self-control. These variables accounted for an additional 40% of the variance for boys (50% for girls) in first grade externalizing symptoms after controlling for externalizing symptoms in kindergarten.