| The Flynn Effect is actually no longer observed. [0] There is a multi-decade IQ drop in multiple European countries with otherwise world-leading Education systems. More interestingly the drop is also happening intra-family which defeats the initial theory of a dumbing down of the gene pool. Currently the best theory is that there is an environmental cause. If I'm allowed to speculate my money is on diesel engine NO2 exposure [1], plasticizers [2], and flame retardants [3], probably in that order. [0] https://edition.cnn.com/2018/06/13/health/falling-iq-scores-... [1] https://pubmed.ncbi.nlm.nih.gov/26426942/ [2] https://pubmed.ncbi.nlm.nih.gov/25493564/ [3] https://pubmed.ncbi.nlm.nih.gov/31952890/ |
The study underlying that CNN article only used three decades of data and only for Norwegian males. Also note that their cohort IQ delta is < 2 points across a decade which is well within error margin.