This morning’s lesson is taken from The Gospel According to Joe Henrich: Chapter 17 Page 320
The first thing to realize is that you are much smarter than you would otherwise be because you’ve tapped into and downloaded an immense repository of mental apps from a vast pool of culturally inherited know-how and practices. The full list of things I’ve discussed is rather long and is scattered over many chapters. Here’s a brief list of a few of the mental tools you have at your disposal, which you never would have figured out on your own: base-10 counting, fractions, temporal partitions (minutes, hours, days, etc.), pulleys, fire, wheels, levers, eleven basic color terms, wind power, writing, elastic energy, multiplication, reading, kites, writing, a variety of knots, 3D spatial reference systems, and subordinating conjunctions. And, as I noted in chapter 16, while some of these are installed in your brain as firmware, some are now hardware. Since you are reading this, we can bet that your corpus callosum— the information highway connecting your brain hemispheres— is thicker than it might otherwise be.
Now, if we were to begin moving back in time, century by century, picking adults at random from all living humans and seeing what culturally acquired mental tools they had in their heads, we’d find that the ones now in your head would gradually disappear. Often, we’d find other very cool mental tools and abilities, such as the mental abacus, improved underwater vision, tons of subtle farming heuristics, mental maps for spotting animal tracks, and an acute sense of smell. As I’ve noted, many of these mental tools come with some costs. For example, acquiring eleven basic color terms improves our ability to distinguish between colors with different verbal labels, although it also degrades our ability to distinguish shades with the same label. And although biological categories can highlight important relationships (penguins are a type of bird, so they lay eggs), these categories can also conceal other relationships (penguins are aquatic, so they have solid bones, unlike most other birds). Nevertheless, it’s still the case that past peoples would be less good at doing many of the things we now think are “smart.” For example, if we measured IQ scores and scaled them using today’s scale, we’d find that at our second stop, in in 1815, the average American would have an IQ below 70. (Hunter’s note: Check out Stanford Psychologist talking about The Age of IQ and read about the Growth Mindset here.)
Recall that we saw just how well less enculturated humans— that is, children— performed against apes, both young and old. If humans were equipped with more powerful genetically installed hardware, we’d expect that these kids, who have much bigger brains than the apes they were competing against, would have mopped up the floor with their hairy brethren. Instead, they mostly tied in a wide range of cognitive domains.
Where the kids did excel was in the domain of social learning, as we saw in both chapter 2 and again in the cumulative cultural transmission experiments in chapter 12. Of course, as the kids get older and have time to download those aforementioned apps, they will rapidly surpass the apes in all the cognitive domains. The young apes, by contrast, will get older but no better at these cognitive tasks.
This of course raises the question of where all these elaborate psychological tools, complex artifacts, and training regimes that make us smarter come from, if not from the genius of individual minds. The answer is that they arose via cumulative cultural evolution from our collective brains, often without anyone realizing what was going on. Because of the combination of our powerful cultural learning and our sociality, information in the form of ideas, tools, practices, insights, and mental models can flow among individuals, recombine with other such information, and gradually improve as the selective filters of human learning, reproductive success, and intergroup competition toss some stuff on the trash heap of history and push other stuff onward to the next generation.
Unique feats of genius are rare, since once the tectonic forces of cumulative cultural evolution have closed the knowledge gap to a point where one person can step across, intellectual histories show that multiple people often independently manage to take that step. (Hunter’s Note: Though advertisers have figured out how to highjack the emotion of awe to convince you that some people are magically gifted. You can read about that here.)
I illustrated the importance of the size and social interconnectedness of collective brains in Tasmania, Northern Greenland, and Oceania as well as in the laboratory. Not only do larger collective brains generate more and faster cumulative cultural evolution, but if the size or interconnectivity of a group suddenly shrinks, that group can collectively begin losing cultural know-how over generations. This all means that the power of a group’s collective brain depends on its social norms and institutions. This is why, in chapters 9 and 10, I emphasized the importance of affinal relatives (in-laws) and both exchange and ritual ties in hunter-gatherers, because it’s these culturally constructed relationships— not genealogical relatedness— that nourish and enlarge their groups’ collective brains. Thus, these kinds of social institutions are part of the reason why expanding populations, such as speakers of the Pama-Nyungan, Inuit, and Numic languages, had and maintained a technological advantage over those they replaced. In humans, sociality and technological know-how are intimately interwoven.
Of course, we humans do have superior abilities to build causal models of how the world works. But we should ask why. My view is that first cultural evolution began producing increasingly complex practices and technologies, which involved things like chemical reactions (burnt sea shells in maize), compressed air (blowguns), aerodynamics (straight, smooth spears), extended moment arms (spear-throwers), and elastic energy (bows), just to name a few. To be able to more effectively learn and retransmit these valuable bits of culture, our species needed to be able to “back out,” or reverse engineer, what I’ve called mini causal models. These help the learner, in adapting to a variety of circumstances, make sure he or she is achieving the required goals or subgoals for the task. For example, straightening a spear shaft often requires a complex process involving soaking, heating, rubbing, and polishing. A learner has to understand that the procedure is in the service of straightening, balancing, and smoothing the spear, because straighter, smoother, and more balanced spears can be reliably thrown with greater accuracy. With this in mind, someone crafting a spear can periodically examine the shaft for smoothness, balance, and straightness and also test its flight for accuracy. If it’s not accurate, she knows what to do: more rubbing and polishing. That’s the beginning of a causal model because it realizes that this protocol causes (or is supposed to cause) straightness, smoothness, and balance, and these characteristics are then supposed to cause predictable flight patterns that favor greater accuracy.
The point is that being able to construct or acquire these mini-models of causality evolved genetically because it improved cultural transmission. The selective pressures that drove this evolutionary process were produced by the emergence of increasingly complex tools, practices, and technologies. By this view, the ability to construct mini causal models didn’t cause fancy tools and practices. The cultural evolution of increasingly sophisticated tools and practices first drove the emergence of this cognitive ability, and then the two entered into a culture-gene coevolutionary duet. Consistent with this, we saw that observing a demonstrator use an artifact fired up our causal inference machinery more readily than the world simply presenting us with the same causal information. Overall, we are smarter than other animals for a bunch of reasons, both cultural and genetic, but the ultimate causal explanation is that our species found a bridge across the Rubicon, and cumulative cultural evolution finally got some traction on the other side.
So, yes, we are smart, but not because we stand on the shoulders of giants or are giants ourselves. We stand on the shoulders of a very large pyramid of hobbits. The hobbits do get a bit taller as the pyramid ascends, but it’s still the number of hobbits, not the height of particular hobbits, that’s allowing us to see farther.