Peak Brain
We all have heard of “Peak Oil” and most have used the phrase “peak performance”. The first has probably passed, the second keeps increasing, judging by Olympic results. However, a longer term concern is “peak brain”.
It is well known that Neandertal people had larger brains than do we, Homo Sapiens Sapiens. So clearly having a larger brain is not the only factor in long term survival. But the fact that Neandertals lived in a cold, ice-age climate, while we came out of Africa, raises an interesting question: is brain size related in any way to climate?
A recently published paper by Jeff Morgan Stibel titled “Climate Change Influences Brain Size in Humans” claims that there is a correlation, and that our currently warming climate does not bode well for our brains size.
We already see signs of this effect all around the world. Many people have a sense that things are getting worse, and people stupider. Cory Doctorow coined a term to describe one aspect of this: enshittification. Of course, a short-term observation has little to do with the long-term trend. But the long term trend just aggravates what many see. The true effects won’t become obvious for millennia, assuming other factors allow us to survive that long.
When did we pass “peak brain”? The article mentioned earlier doesn’t commit to a number, but implies the peak may have been 15,000 years ago. The article also says that there is a considerable lag between changed conditions and evolutionary response. In the Discussion, Stibel says that “…the present period of accelerated warming could lead to increased evolutionary pressure on the human brain.” He concludes with “…there is some genetic evidence to suggest that brain size, general cognitive ability, and educational attainment are all being selected against in modern human populations… Even a slight reduction in brain size across extant humans could materially impact our physiology in a manner that is not fully understood.”
There is a more accessible summary of this article at ScienceAlert.com.
All of this is only a long-term concern. We have far more immediate problems to address. But address them we must, if we are to have any hope of addressing this, and other, long-term problems.