It’s coincidental with the human adoption of farming.
So far it looks like no hypothesis holds water. For example this one about farming is talking about a timeframe of 10.000 years. The shrinkage started 100.000. So there is a 90.000 years gap, that is left unexplained
Then in 2023 DeSilva revised his argument in (link above, in the description), extending the date back, still not giving anwers about the shrinkage observed since 100.000 years ago.
yeah, from the last 3,000 to within the last 10,000 years, with the sharp decline ~5,000 years ago… which does line up with widespread adoption of agriculture still.
Of course you can choose to believe what you want.
The point I was trying to make is that there is no scientific consensus on the topic about how global the decline was, when it began and why it happened - as well as if it is related to the formation of complex societies, farming, language, dietary changes, temperature, or body size.
So far it looks like no hypothesis holds water. For example this one about farming is talking about a timeframe of 10.000 years. The shrinkage started 100.000. So there is a 90.000 years gap, that is left unexplained
and if we estimate farming was 10,000 years ago, we can’t rule out one influenced the other.
Yes, DeSilva published the 2021 paper you linked. In 2022 he got criticism from Villmoare and Grabowski (see: Did the transition to complex societies in the Holocene drive a reduction in brain size? A reassessment of the DeSilva et al. (2021) hypothesis). Then in 2023 DeSilva revised his argument in (link above, in the description), extending the date back, still not giving anwers about the shrinkage observed since 100.000 years ago.
yeah, from the last 3,000 to within the last 10,000 years, with the sharp decline ~5,000 years ago… which does line up with widespread adoption of agriculture still.
Of course you can choose to believe what you want.
The point I was trying to make is that there is no scientific consensus on the topic about how global the decline was, when it began and why it happened - as well as if it is related to the formation of complex societies, farming, language, dietary changes, temperature, or body size.
Agreed. That is why we are here speculating.
This is what makes it a super interesting topic!