Wednesday, January 4, 2023

My posts on Substack

I have lately been posting on Substack and not here. My aim is to write longer articles that build on earlier posts from Evo and Proud. Some of them may eventually be consolidated into a book. Here are the ones to date:


Recent cognitive evolution


West Africans


In West Africa, mean cognitive ability seems to be higher in populations closer to the Niger—the main conduit of trade between the coast and the interior. Trade selects for cognitive ability, either directly through its cognitive demands or indirectly through a consequent increase in social complexity.


Ashkenazi Jews


For almost a millennium, Ashkenazi Jews saw their mean cognitive ability steadily increase from one generation to the next. That increase ended in the 20th century and has given way to a noticeable decline since the 1970s.




In terms of GDP per capita growth, northwest Europe began to surpass the rest of the world during the fourteenth century. This was before the conquest of the Americas, the invention of printing, the Atlantic slave trade, and the Protestant Reformation.


The high mean IQ of Europeans is relatively recent in origin, as is that of East Asians. Both of these “IQ plateaus” arose largely during the time of recorded history.


In the European world, cognitive evolution was driven by the middle class having more babies than everyone else. That baby boom ended in the late 19th century. There then ensued a decline in cognitive ability from one generation to the next.


French Canadians


In French Canada, two alleles for Tay-Sachs arose independently, and over a short time span, in two adjoining areas that had few British or American merchants. Did that vacant niche favor the reproductive success of French Canadians with the right abilities?


Gene-culture coevolution




Increased longevity is associated with 217 of the 420 genetic variants that are specific to the Parsi mitochondrial genome. Others are associated with reduced sperm motility, Parkinson's, Alzheimer's, and cognitive ability. Did Parsi culture select for a slower life history?


Why are East Asians more collectivistic? Why is their approach to thinking more relational and less abstract? They may have been steered in that direction by the requirements of rice farming. 

Sexual selection for hair, eye, and skin color


Europeans have many hair and eye colors. Those two polymorphisms arose about the same time in ancestral Europeans, while not sharing the same genetic causes. They also differ significantly between men and women.

Skin color is perceived through the lens of a mental algorithm that initially arose for gender recognition. People can tell whether a face is male or female even if the image is blurred and provides no other useful information than its hue and luminosity.

Human races: do they exist?

Do genes vary a lot more within human populations than between them? That seems to be the current wisdom. Yet we see the same pattern elsewhere in the animal kingdom—not only with subspecies but also with related species that are nonetheless distinct from each other anatomically and behaviorally.