>Substantial gains in GA were apparent from the mid 1950s (test years) to the end 1960s–early 1970s, followed by a decreasing gain rate and a complete stop from the mid 1990s. [...] It is concluded that the Flynn effect may have come to an end in Norway.
The single and/or the first children have higher IQ, so the Flynn effect is a reverse to the number of children per family, ie. it is a reverse to that graph:
The single and/or the first children have higher IQ, so the Flynn effect is a reverse to the number of children per family, ie. it is a reverse to that graph:
https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?location...
And on the other side of the world - the "one child” policy results are in:
"An increase of intelligence in China 1986–2012" https://www.sciencedirect.com/science/article/pii/S016028961...
https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?location...