Flynn effect and its reversal are both environmentally caused
Abstract
Using administrative register data with information on family relationships and cognitive ability for three decades of Norwegian male birth cohorts, we show that the increase, turning point, and decline of the Flynn effect can be recovered from within-family variation in intelligence scores. This establishes that the large changes in average cohort intelligence reflect environmental factors and not changing composition of parents, which in turn rules out several prominent hypotheses for retrograde Flynn effects.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- June 2018
- DOI:
- 10.1073/pnas.1718793115
- Bibcode:
- 2018PNAS..115.6674B