Adolescents’ intelligence is related to family income

• Previous results suggest that family income is not related to intelligence.
• We find that family income is related to intelligence.
• Methodological and substantive reasons for the difference are discussed.

In a recent article Lemos, Almeida & Colom (LAC, 2011) argued that adolescents’ intelligence is related to parents’ educational levels but not to family income. We examine their finding in two large, nationally representative American samples and find that in these samples (log) income had a strong positive relationship with intelligence.