Prior research indicates that children who experience stressful life events are at risk of developing emotional difficulties and displaying internalizing behavior, yet few studies have looked at the sibling relationship as a moderating factor against these risks. Furthermore, there is conflicting research examining the link between stressful life events and externalizing behaviors. The authors conducted a two-wave longitudinal study to determine the extent to which sibling relationship moderates risks in siblings experiencing stressful events. Data were gathered through the Avon Longitudinal Study of Parents and Children (ALSPAC), with a total of 196 families agreeing to participate after meeting the selection criteria. Interviews were conducted with families twice: first, at baseline and again, two years later. Interviews measured number and qualtity of stressful life events, quality of sibling relationship, quality of mother-child relationship, children’s externalizing and internalizing behaviors, socioeconomic status, age, and gender. The study found that positive sibling relationships positively influenced the relationship between stressful life events and internalizing symptomatology, but not the relationship between stressful life events and externalizing symptomatology. The study also found that the protective effect is not dependant upon the quality of the mother-child relationship.
This study is the first of its kind. No other study has examined if sibling relationships are protective for children who experience stressful life events. The choice of a longitudinal design was a strength, because the results are more likely to be attributed to a causal relationship between the positive sibling relationship and the amelioration of internalizing symptomatology. Also, the measures utilized the responses of multiple respondents, making a more accurate determination of scale. However, there may be plausible rival hypotheses due to variables that may not have been included in the research. Maturation may be a threat to internal validity, as children who are two years older might show improved internalizing behaviors. This study would have improved with the implementation of a control group of children who experience stressful events, but do not have a sibling. The control group would have evidenced that the protective effect of the sibling relationship is responsible for decreased internalizing behaviors.
Gass, K., Jenkins, J., and Dunn, J. (2007). Are sibling relationships protective? A longitudinal study. Journal of Child Psychology and Psychiatry, 48(2), 167-175.