Abstract
Some evidence exists for the phenotypic association of problem behaviour in early childhood with temperament in infancy, but little is known about the genetic and environmental mechanisms mediating this association. At the ages of 14, 20, 24, and 36 months, mothers of twins completed the Colorado Childhood Temperament Inventory (CCTI; Buss & Plomin, 1984; Rowe & Plomin, 1977). At age 4, problem behaviour was assessed using maternal reports on the Child Behavior Checklist (CBCL/4-18; Achenbach, 1991). The temperamental trait of Emotionality at all four prior age points correlated significantly with the CBCL Total Problem Score at 4 years as well as with the broad-band groupings of Internalising the Externalising. In addition, Shyness at all four ages correlated significantly with the broad-band grouping of Internalising. Longitudinal behavioural genetic analyses indicated that these phenotypic predictions from early temperament to later behaviour problems are largely due to genetic factors.
