November 25, 2025
Nature vs nurture? Comment wars
IQ differences of identical twins reared apart are influenced by education
Identical twins, different schools, different IQs — cue comment chaos
TLDR: A study of 87 identical twins raised apart links different schooling to bigger IQ gaps and less similarity. The community is split between “school trains test scores,” confusion over what 15 points means, and skeptics questioning sample size—fueling a fresh nature-vs-nurture showdown.
A new study combed through 87 pairs of identical twins raised apart and split them by how similar their schooling was. The hotter the classroom differences, the bigger the IQ gap: about 6 points for similar schooling, 12 for somewhat different, and 15 points when education diverged wildly. The twins’ “similarity score” (intraclass correlation, aka how alike their IQs are) dropped from 0.87 to 0.56 as schooling diverged — and the comments lit up.
One camp shouted: education matters more than we thought, with parents and twin-watchers linking to the wild doc Three Identical Strangers. Others pumped the brakes: “Are we just training for the test?” asked one, wondering if more school simply boosts test-taking skills. Curious readers asked what 15 points means in normal life; replies boiled it down to moving from everyday average to clearly “noticeably sharper.”
Then came the data detectives. A skeptical commenter did the math on the sample breakdown and asked if the big claims rest on only 10 pairs — sparking calls for more transparent, pair-level data. One popular take: nature is strong, but nurture “changes the scoreboard.” Another linked the nuance to height: twin studies show genetics loom large when basic needs like nutrition are met. Meme-wise, commenters joked: “One twin got Hogwarts, the other got detention,” and “Nature hired nurture as a consultant.” It’s the internet’s favorite fight — now with twins and test scores
Key Points
- •Dataset includes 87 monozygotic twin pairs reared apart with individualized IQ and biographical data.
- •Pairs were grouped by schooling similarity: similar, somewhat dissimilar, and very dissimilar.
- •Mean twin IQ differences increased with schooling divergence: 5.8, 12.1, and 15.1 points respectively.
- •ICC decreased with schooling divergence: 0.87 (similar), 0.80 (somewhat dissimilar), 0.56 (very dissimilar).
- •Authors question using aggregate ICC as a measure of genetic influence on IQ and recommend focusing on individual pairs and data transparency.