The Nature and Predictors of Undercontrolled and Internalizing Problem Trajectories Across Early Childhood Kristin S. Mathiesen & Ann Sanson & Mike Stoolmiller & Evalill Karevold Published online: 3 September 2008 # Springer Science + Business Media, LLC 2008 Abstract Using growth curve modeling, trajectories of undercontrolled (oppositional, irritable, inattentive and overactive behaviors) and internalizing (worried, sad and fearful) problems from 18 months to 4.5 years were studied in a population based sample of 921 Norwegian children. At the population level, undercontrolled problems de- creased and internalizing problems increased with increas- ing age. Child temperament and family factors present at 18 months predicted 43% of the stability and 20% of the linear changes in undercontrolled problems and 30% of the stability and 7% of the linear changes in internalizing problems. Persisting effects of child and family factors from 18 month were found on the two problem dimensions over and above the impact of changes in the same risk factors. Lower initial level of partner support and higher initial level of child emotionality predicted higher slope of under- controlled problems and higher initial level of family stress predicted higher slope for internalizing problems. As expected, time to time change (t1 to t2 and t2 to t3) in risk factors predicted time to time change in problem scores as well. The study shows the significance of early emerging internalizing and undercontrolled problems, the need to consider their pathways separately from very young ages, lasting effects of early experiences, and the importance of a dynamic approach to the analysis of risk. Keywords Undercontrolled and internalizing problems . Temperament . Maternal depression . Partner support . Growth curve modeling Introduction A major theme in studies of development is the possibility that there may be lasting effects of early experiences on psychological outcomes (O’Connor 2006). The question of whether or not the individual returns to normal develop- ment following negative life events or restricted periods of family adversity has challenged researchers for years (Campbell 1995; Strohschein 2005). The answer is of central theoretical as well as practical significance for early intervention and prevention efforts (Dawson et al. 2000). This paper explores change in both undercontrolled behavior problems (the core categories of externalizing items except aggressive or destructive behaviors) and internalizing problems across early childhood, identifying predictive factors accounting for initial problem status at age 18 months, time to time change within the develop- mental period (18 months to 2.5 years and 2.5 years to 4.5 years) and long term change over the entire develop- mental period (18 months to 4.5 years). While a number of studies have examined problem behaviors among children from three years of age onwards, there is less knowledge about problem behaviors among younger children and J Abnorm Child Psychol (2009) 37:209–222 DOI 10.1007/s10802-008-9268-y K. S. Mathiesen (*) : E. Karevold Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, N-0403 Oslo, Norway e-mail: krma@fhi.no K. S. Mathiesen Centre for Child and Adolescent Mental Health, Eastern and Sothern Norway, Oslo, Norway A. Sanson Department of Paediatrics, University of Melbourne, Victoria, Australia M. Stoolmiller 137 1/2 W Washington, Marquette, MI 49855, USA