Intelligence is not like height
Debate over whether intelligence is strongly heritable, like height, quickly expands into questions about what IQ tests actually measure, how reliable they are, and how much genetics versus environment shapes cognitive ability. Commenters cite twin studies and “missing heritability” in genome research, argue over biases and limitations of IQ as a proxy for intelligence, and highlight how the topic becomes entangled with race, social class, and political taboos. Many conclude that both genes and environment matter, but that simplistic genetic determinism and race-based claims about IQ are scientifically weak and socially dangerous.
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.