Schooling linked to IQ differences in identical twins
Schooling explains major IQ differences in identical twins raised apart, challenging decades of research.
Why it matters
- Schooling plays a significant role in IQ differences among identical twins raised apart.
- Challenges the notion that genetics alone determine intelligence.
By the numbers
- Study analyzed 87 twin pairs from 19 studies.
- Twins with similar schooling had IQ differences of 5.8 points.
- Twins with very different schooling had IQ differences of 15.1 points, similar to unrelated individuals.
The big picture
- The study suggests that environmental factors, particularly schooling, significantly impact IQ.
- Challenges the historical emphasis on genetics in determining intelligence.
What they're saying
- Some commenters suggest that genes determine the IQ ceiling, while nurture determines how close one gets to that ceiling.
- Others question the focus on schooling over primary caregivers and the societal implications of IQ measures.
Caveats
- Small sample size for twins with very dissimilar schooling (only 10 pairs).
- More individualized data needed to fully understand the impact of schooling.
What’s next
- Researchers suggest a shift from large-scale aggregate studies to in-depth case studies of individual twin pairs.
- Call for more sharing of de-identified, individualized data to improve accuracy.