Browsing by Author "Malkamäki, Kristiina"

Objectives: Temperament traits have been associated with externalizing symptoms both cross-sectionally and longitudinally at different stages of childhood. However, the amount of longitudinal studies to date is limited. It is also unclear whether temperament traits assessed as early as in infancy predict externalizing symptoms longitudinally. Also, research is needed about how change and stability in temperament traits are associated with externalizing symptoms. The aim of this thesis is to study whether early temperament traits, assessed between the ages of 4.76–12.39 months, and their stability and change between the ages of 4.76–12.39 months and 7–11 years predict externalizing symptoms between the ages of 7–11 years. Methods: The samples of this study were from the Prediction and Prevention of Preeclampsia and intrauterine growth restriction (PREDO) project. The main subsample (N=919) included children whose mothers had filled the Infant Behavior Questionnaire Revised (IBQ-R) when the child was 4.76–12.39 months old, the Temperament in Middle Childhood Questionnaire (TMCQ) when the child was 7–11 years old and both the Child Behavior Checklist (CBCL) and Strengths and Difficulties Questionnaire (SDQ) when the child was 7–11 years old. A second subsample (N=581) included children who also had paternal reports of the IBQ-R collected between the ages of 5.19–11.89 months. The associations between temperament traits, their stability and change and externalizing symptoms were investigated with linear regression analysis. Maternal education, age, relationship status, depressive symptoms and child sex and age were controlled for in the analyses. Results and conclusions: Higher levels of externalizing symptoms were predicted by higher levels of infant negative emotionality and lower levels of infant orienting/regulatory capacity. The associations were explained by small to moderate rank-order stability between infancy and middle childhood. However, the associations were small and not completely independent of covariates, informants or the questionnaires used to measure externalizing symptoms. At school age, a change toward higher levels of negative emotionality, higher levels of extraversion or lower levels of effortful control from infancy was associated with higher externalizing symptoms independent of covariates. As a new finding, infant and school age levels of extraversion were found to have moderating effects on each other’s associations with externalizing symptoms. The results are in line with previous literature suggesting that the predictive utility of temperament traits in infancy on externalizing problems in school age is limited. The development of temperament traits over time appears to be more relevant to externalizing symptoms in school age than their levels in infancy. More longitudinal research of the association between temperament trait stability, change and externalizing symptoms is needed, preferably including multiple informants and assessments.