An examination of early socioeconomic status and neighborhood disadvantage as independent predictors of antisocial behavior: A longitudinal adoption study.

The present study examined early socioeconomic status (SES) and neighborhood disadvantage (ND) as independent predictors of antisocial behavior (ASB) and addressed the etiology of the associations (i.e., genes versus the environment) using a longitudinal adoption design. Prospective data from the Colorado Adoption Project (435 adoptees, 598 nonadopted children, 526 biological grandparents of adoptees, 481 adoptive parents, and 617 nonadoptive parents including biological parents of unrelated siblings of adoptees) were examined. SES and ND were assessed during infancy and ASB was evaluated from ages four through 16 using parent and teacher report. Associations between predictors and ASB were compared across adoptive and nonadoptive families and sex. Early SES was a nominally significant, independent predictor of antisocial ASB, such that lower SES predicted higher levels of ASB in nonadoptive families only. ND was not associated with ASB. Associations were consistent across aggression and delinquency, and neither SES nor ND was associated with change in ASB over time. Nominally significant associations did not remain significant after controlling for multiple testing. As such, despite nonsignificant differences in associations across sex or adoptive status, we were unable to make definitive conclusions regarding the genetic versus environmental etiology of or sex differences in the influence of SES and ND on ASB. Despite inconclusive findings, in nonadoptees, results were consistent-in effect size and direction-with previous studies in the literature indicating that lower SES is associated with increased risk for ASB.

Heritability × SES Interaction for IQ: Is it Present in US Adoption Studies?

An interaction between socioeconomic status (SES) and the heritability of IQ, such that the heritability of IQ increases with higher SES, has been reported in some US twin studies, although not in others, and has generally been absent in studies outside the US (England, Europe, Australia). Is such an interaction present in US adoption studies? Data from two such studies, the Texas and the Colorado Adoption Projects, were examined, involving 238-469 adopted children given IQ tests at various ages. A mini multi-level analysis was made of the prediction of the IQs by the SES of the rearing home (a composite of parental education and occupation), by the birth mother's intelligence, and by the interaction of the two. Neither study showed any substantial heritability × SES interaction: the effect size estimates in units comparable to twin moderation models were negative (- 0.042 and - 0.004), and the meta-analytic estimate for the combined analysis was - 0.27 (SE = 0.042) with a 95% confidence interval of - 0.109 to 0.054. Thus, while we cannot rule out positive moderation based on our two studies, the joint agreement across these studies, and with the non-US twin studies, warrants attention in further research. SES may not fully capture proximal familial-environmental aspects that moderate child IQ.

Temperament, childhood illness burden, and illness behavior in early adulthood.

OBJECTIVE: Illness behaviors-or responses to bodily symptoms-predict individuals' recovery and functioning; however, there has been little research on the early life personality antecedents of illness behavior. This study's primary aims were to evaluate (a) childhood temperament traits (i.e., emotionality and sociability) as predictors of adult illness behaviors, independent of objective health; and (b) adult temperament traits for mediation of childhood temperament's associations. METHOD: Participants included 714 (53% male; 350 adoptive family and 364 control family) children and siblings from the Colorado Adoption Project (CAP; Plomin & DeFries, 1983). Structural regression analyses evaluated paths from childhood temperament to illness behavior (i.e., somatic complaints, sick days, and medication use) at two adulthood assessments (CAP years 21 and 30). Analyses controlled for participant age, sex, family type (adoptive or control), adopted status, parent education/occupation, and middle childhood illnesses, doctor visits, and life events stress. RESULTS: Latent illness behavior factors were established across 2 adulthood assessments. Multilevel path analyses revealed that higher emotionality (fearfulness) in adulthood-but not childhood temperament-predicted higher levels of illness behavior at both assessments. Lastly, lower emotionality-fearfulness partially mediated the effect of higher childhood sociability on adult illness behavior. CONCLUSIONS: Results suggest the importance of childhood illness experiences and adult emotionality (fearfulness) in shaping illness behavior in early adulthood. They also suggest a small, protective role of childhood sociability on reduced trait fearfulness in adulthood. These findings broaden our understanding of the prospective links between temperament and illness behavior development, suggesting distinct associations from early life illness experiences. (PsycINFO Database Record (c) 2019 APA, all rights reserved).