Intelligence is not like height

Original Article ↗ Hacker News Discussion ↗

Tone and Purpose of the Article

  • Several commenters found the article overly sarcastic and ideologically driven, which they felt weakened its argument.
  • Some readers said the main point (“intelligence isn’t like height”) was trivial or unclear; others saw it as targeting claims that IQ is strongly genetic and used to justify racial hierarchies.
  • A few labeled the piece “bait” or “garbage,” arguing it attacks a strawman and omits key evidence (e.g., twin studies).

Heritability, Genetics, and the “Missing Heritability” Problem

  • Multiple comments cite twin and adoption studies suggesting high heritability of IQ (often ~0.5–0.8), contrasting this with weaker results from SNP/GWAS work.
  • The “missing heritability” problem is raised: traditional methods imply strong genetic influence; current molecular methods capture only a small fraction.
  • Others stress that heritability is widely misunderstood: it measures variance within a given population and environment, not genetic determinism.
  • Some argue heritable traits are not necessarily genetic (e.g., alcoholism in alcohol-using societies).

IQ vs. Intelligence and Test Validity

  • Debate over whether IQ meaningfully measures “intelligence”:
    • Pro side: IQ/g correlates with academic/occupational success, income, various life outcomes, and is relatively robust; standardized exams are defended as minimally biased.
    • Skeptical side: IQ is a narrow construct tied to formal education, culturally skewed, partly “cultural trivia,” with test–retest reliability and within-person variation comparable to or larger than many group differences.
  • Several note that “intelligence” itself lacks a clear definition, making claims of IQ–intelligence correlation conceptually shaky.

Race, Ethnicity, and Taboo

  • Strong disagreement over studying IQ differences between racial/ethnic groups:
    • Some say such work is inherently racist or scientifically incoherent because “race” is a social, not genetic, category.
    • Others argue genetic group differences are plausible and suppressing such research (including via hate-speech laws) is anti-scientific.
  • Environmental and historical factors (slavery, nutrition, education, endogamy, discrimination) are repeatedly cited as alternative explanations for group IQ gaps.

Environment, Development, and Policy

  • Several emphasize environmental impacts (nutrition, clean water, education, stress, family dynamics, brain drain) on both IQ and mental illness analogies.
  • One thread focuses on low measured IQ in some developing countries, arguing it’s a major constraint on governance and growth and should be studied; critics worry such framing excuses ignoring basic improvements.