Tuesday, December 22, 2020

History of big brains

Razib Khan posted a nice essay on IQ:
Homo sapiens are very smart. They are very smart because they have large brains. This is not controversial. In relation to our body size, humans have bulging craniums housing large brains. About 20% of our caloric intake feeds our brain when we’re resting even though it’s only 2% of our body weight. It’s a calorically expensive organ. ...

Around 200,000 years ago the growth of our brains leveled off, probably due to biological constraints. ...

And H. sapiens and its brain found its barrier 200,000 years ago. In fact, the largest brained humans seem to have lived during the Ice Age, not today. Since the transition to farming our brains have been shrinking.

European Neanderthals had the big brains, so they may have been smarter than us.
Consider the polymath John von Neumann. A basis for the character of Dr. Strangeglove, von Neumann was one of the most brilliant individuals of the 20th century. The theoretical physicist Edward Teller said of von Neumann that he “would carry on a conversation with my 3-year-old son, and the two of them would talk as equals, and I sometimes wondered if he used the same principle when he talked to the rest of us.”
Possible. I have had many conversions with 3-year-olds, and about 90% of adult conversations are not much different. The adults have a largers vocabulary, and a broader range of experiences to draw on. But otherwise, they carry on conversations like 3-year-olds. It is usually easier to deal with them if I think of them as 3-year-olds in adult bodies. For example, in talking politics, I have never heard a Biden supporter converse at more than a 3-year-old level.
Tests are imperfect. But what is the alternative? Over the past few years graduate schools have been removing the GRE as a requirement for admission. What will the consequence be? If the history of China is any guide, those with connections and pedigree will benefit. Without a hard-to-fake entrance exam, recommendations from those you trust will loom large again. The abolition of the GRE will be a back door through which the “letter of introduction” returns. Who will be hurt by this? Who will benefit? There are many answers here, but one thing seems obvious: those without connections will suffer.
Yes, we are moving away from being a meritocracy. Universities are filling up with lower-IQ students.

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