How do childhood intelligence and early psychosocial adversity influence income attainment among adult extremely low birth weight survivors? A test of the cognitive reserve hypothesis.

Perinatal and later postnatal adversities have been shown to adversely affect socioeconomic trajectories, while enhanced early cognitive abilities improve them. However, little is known about the combined influence of these exposures on social mobility. In this study, we examined if childhood IQ moderated the association between four different types of postnatal adversity (childhood socioeconomic disadvantage, childhood sexual abuse, lifetime psychiatric disorder, and trait neuroticism) and annual earnings at 30-35 years of age in a sample of 88 extremely low birth weight survivors. Our results suggested that higher childhood IQ was associated with greater personal income at age 30-35. Extremely low birth weight survivors who did not face psychological adversities and who had higher childhood IQ reported higher income in adulthood. However, those who faced psychological adversity and had higher childhood IQ generally reported lower income in adulthood. Our findings suggest that cognitive reserve may not protect preterm survivors against the complex web of risk factors affecting their later socioeconomic attainment.