IQ’s link to income mostly reflects environment’s link to both

Evidence

The most immediate support for the IQ theory of social inequality which we will call “IQism”— flows from two substantial relationships. The first is the significant association between socioeconomic background and childhood IQ. Thus, according to our research, having a parent in the top decile in socioeconomic status gives a child a 42 percent chance of being in the top fifth in IQ, while having a parent in the bottom socioeconomic status decile gives him only a 4.9 percent chance. The second is the important association between childhood IQ and later economic success: An individual in the top childhood IQ decile is nearly four times as likely to achieve the highest income quintile as an individual from the bottom IQ decile. — Samuel Bowles and Herbert Gintis, Schooling in Capitalist America, 1077

Categorization

• recurring: this claim recurs 2 times within its source
• XREF: connects to: Mixed-race children’s IQ tracks rearing environment, not racial genetics — Harriet A. Washington, A Terrible Thing to Waste, 119; Intelligence develops from environment and experience rather than genetic inheritance; With heritability well below 1.00, IQ must be subject to substantial environmental influences, though genetic influence increases with age while shared family environment effects shrink by late adolescence. — Intelligence: Knowns and Unknowns (+5 more)

Broader Connections

• Mixed-race children’s IQ tracks rearing environment, not racial genetics #corroborates (0.90) — Harriet A. Washington, A Terrible Thing to Waste, 119
• Intelligence is malleable and shaped by environment, not fixed by heredity #corroborates (0.85) — Harriet A. Washington, A Terrible Thing to Waste, 54
• Intelligence develops from environment and experience rather than genetic inheritance #corroborates (0.80)
• Class-based educational inequality persists almost unchanged when IQ is held constant #corroborates (0.80)