# Bernt Bratsberg and Ole Rogeberg Back to [[Reverse Flynn Effect and EdTech]] **Role:** Economists; authors of the key Norwegian Flynn-reversal study - Their 2018 paper "Flynn effect and its reversal are both environmentally caused," *PNAS* 115(26):6674–6678. - Data: **736,808** Norwegian conscript scores, men born 1962–1991. - Scores rose to a peak for men born about 1975, then fell, **including within families (brothers)**. - Conclusion: the cause is environmental, not dysgenic. They do not identify the specific cause. - ⚠️ Affiliation from memory: Ragnar Frisch Centre for Economic Research, Oslo. - **Relevance:** this is the strongest IQ evidence for a reversal, but it ends at the 1991 birth cohort, before Gen Z.