Family socioeconomic status may be correlated with intelligence test scores and brain development

Family socioeconomic status during childhood appears to correlate with intelligence test scores and measures of brain development, according to a study published in Communications Biology. The study involved over 200 Japanese children and took place over a 3-year period.

The socioeconomic status of a child’s family—measured as family income and the length of time parents had stayed in education—has been linked to various measures of cognitive ability and brain development in prior studies. These links are likely the result of many biological and environmental factors, but it is still unclear how the correlations may change during development.

Hikaru Takeuchi and colleagues investigated the relationship between brain structural development, psychological test scores, and family socioeconomic status in children between 5- and 18-years-old who were followed for 3 years. The research involved a widely used test, the Wechsler Intelligence Scale, with different versions for children above or below 16-years-old. The tests measure verbal, spatial, and numerical skills. They found that children from families with a higher socioeconomic status generally achieved slightly but significantly higher overall IQ and verbal IQ scores, compared to children from families with lower socioeconomic status. However, they did not find any correlation of nonverbal IQ scores alone with socioeconomic status.

The authors also report a correlation between family socioeconomic status and structural changes over time in a part of the brain involved in letter recognition and reading. Though no direct causal relationship can be determined from their observations, the results did show that the correlations became stronger over time. This suggests that any educational interventions may be more effective in early childhood.