This study used data from the longitudinal Christchurch Health and Development Study to examine the extent to which childhood socioeconomic status (SES) could account for differences in adult psychosocial outcomes between Māori and non-Māori in a birth cohort of more than 1000 individuals studied to age 30. Data were gathered on three measures of childhood SES (family SES, family living standards, family income) and adult psychosocial outcomes including mental health, substance use, criminal offending, and education/welfare dependence outcomes. Māori ethnicity was associated with significantly (p<0.0001) poorer scores on the three measures of childhood SES, with estimates of Cohen’s d indicating a moderate effect size. Māori ethnicity was also linked to significantly (p<0.05) greater rates of adverse psychosocial outcomes in adulthood. Controlling for childhood SES reduced the magnitude of the ethnic differences in psychosocial outcomes, but did not fully explain the differences between Māori and non-Māori. Adjustment for childhood SES had the strongest effect on education/welfare dependence, but weaker effects on mental health, substance use, and criminal offending.
