Developmental course of child personality traits and their associations with externalizing psychopathology: Results from a longitudinal multi-informant study in a representative cohort

A representative cohort of six-year old children from the Swiss general population (n ≈ 1200) was assessed in 2006 and re-assessed in 2009 with informant-ratings of personality and externalizing psychopathology. Mean levels of neuroticism (d = 0.80) and to a lesser extent agreeableness (d = 0.37) declined considerably over time on a population-level, but differential stability was high (r range = 0.71-0.95). Age 6 trait-score and trait-change over time in agreeableness related significantly to age 9 externalizing pathology. Path analysis additionally provided evidence for bidirectional covariance between several personality traits and externalizing psychopathology and there were some prospective influences of age 6 psychopathology on subsequent personality change. Differential stability of personality is high, but marked trait-change occurs and is relevant as it prospectively relates to externalizing psychopathology.