Cognitive functioning and behavioral adjustment of internationally adopted children: the role of pre-adoption experiences and adoptive parenting

Adoption studies have demonstrated that there is a remarkable heterogeneity in adopted children’s developmental outcomes. Whereas the majority of adopted children are well-adjusted, a minority shows persistent delays or difficulties in various developmental domains such as cognitive functioning and behavioral adjustment. In the current dissertation we aimed to broaden our understanding of factors in the pre-adoption and in the post-adoption environment that may play a role in explaining this heterogeneity. In specific, we studied (1) associations between adopted children’s cognitive and behavioral adjustment in middle childhood and the type of care (institutional care versus foster care) and the extent of early deprivation they experienced prior to adoption. Furthermore, we tested whether (2) parental sensitivity and parental efficacy buffered the associations between adverse pre-adoption experiences and cognitive and behavioral adjustment.

Two studies were conducted in a sample of 92 Chinese adopted girls who took part in the Chinese Adoptees in the Netherlands (CAN) study, two months, six months and nine years after adoption. Besides, the research question concerning the association between pre-adoption experiences and behavioral adjustment was also studied in a sample of 891 girls who participated in the Leiden Questionnaire study on children adopted from China. Findings of our studies were generally not in line with our expectations. Although the post-foster children had higher intellectual abilities than the post-institutionalized children two and six months after adoption, this group difference had disappeared nine years after adoption. Moreover, there were also no effects of type of pre-adoption care, nor of early deprivation on the other assessed domains of cognitive development (school achievement, executive functioning, and effortful control). Similarly, no effects of type of pre-adoption care nor of early deprivation on behavioral adjustment were found, with the exception of a small, significant association between early deprivation and behavioral adjustment in the Leiden Questionnaire Study. Finally, we did not find strong support for the hypothesized effects of parental sensitivity and parental efficacy in the association between pre-adoption experiences and cognitive development and behavioral development.

These studies led to the conclusion that over time, effects of pre-adoption adversities declined and that they explained little variance in the adopted children’s cognitive and behavioral functioning in middle childhood. Furthermore, there was little evidence for buffering effects of adoptive parenting on these associations. Nevertheless, nine years after their adoption the children were well-adjusted in terms of their cognitive and behavioral functioning. The current studies thus add evidence for the importance of adoption in the care of deprived children.