The evolution of intelligence

In third grade, I took a test—a bunch of us did—an aptitude test I guess. In one part of it, we got these diagrams of shapes—red and yellow angular things—and we had to replicate the shape using multicolored blocks.

It was a snap. I’m still good at that stuff. If that was a job or a sport, I would be the CEO of the Olympic Committee for block-shape-engineeramajig-ing.

But there was another part of the test that wasn’t easy. That was the word association section. I was given a word, and I had to give whoever was running the test—I remember her as a nondescript forty-year old woman with shoulder length brown hair, but that’s probably because I just finished watching the Veronica Mars episode where the dad tries dating (which, my wife noticed, was played by the same lady who played Jeremy’s choreoanimator girlfriend in Sports Nite).

In hindsight, I think that she was trying to measure the timing, not necessarily the words that I chose. The goal is, I think, to measure the speed with which the brain makes connections, not the “quality” of the connections, which is subjective and harder to quality. I gave her words fast enough, but it was important to me and my third-grade brain that there be a real connection between them.

So when the lady gave me the word “pound,” I immediately thought of a dog pound, and a sad little Labrador puppy, yipping despondently behind a cage door. And I thought of where that dog would like to be, out of the shelter and roughhousing with a boy much like myself on a long front lawn somewhere in the suburbs of Americana.

So, with that picture in mind, I said: “Yard.”

When I left the room, though, I almost had a panic attack because I realized suddenly that most people don’t think of a dog pound, they think of the unit of measurement–pound as in “I weight eighty pounds.”

“But wait!” my brain said—can brains say things?—before I could take another step, “A yard is a unit of measurement, too!”

When the call came down a week later that I was to spend Friday afternoons in “Enrichment” class learning about Mayan runes and pretending to play the stock market, I knew that I had fooled the nice lady from Sports Night with my sdrawkcab thinking.


Not the Smartest Shed in the Drawer

Intelligence, Brian Boyd says, comes in two types, and is at least partly the result of two different phases of brain growth which caused by two separate environmental pressures.

The first type of intelligence that humans have is one that understands certain input in fundamentally the same way every time. We process light and sound, for example, in a relatively similar way all over the world. We might have different emotions about light and shadow, but the way we actually process the raw sensory data is the same.

The other kind of intelligence, though, uses experience to inform its (meaning the brain’s) comprehension of what’s going on around it. Seeing a tooth tiger in a particular glade—even hearing a story about a tiger stalking a certain glade—allows humans to understand their environment in complicated ways, to understand the chronological and causal connections between events. The sun rises in that spot no matter what I do, but when the river overflows near Fred’s house, more plants grew in the wet spots.

Boyd writes:

Light and sound operate similarly everywhere, but each environment has its unique flora and fauna. [David] Geary proposes that to cope with such variability, brains evolved a more flexed modularity that permits plasticity (modifiability) in brain development. We can conceive of modularity as having a hard exoskeleton, like a crab’s, for those cognitive systems that process invariant patterns, and a soft internal structure of systems modifiable by experience, accommodating local differences within the constraints of the exoskeleton. (44)

There were two separate pressures that encouraged human brains to evolve into larger, more complicated organs capable of this plasticity.

A Brains Arms Race

There was, first off, pressure to work together in bands, thereby becoming what Boyd calls “superpredators” hunting “megafauna” (which, when Boyd puts it like that, makes me feel like a total badass even though I’m pretty sure I just referenced Veronica Mars like five minutes ago).

Evolving so that we could work together and use tools like flint axes and fire made us dangerous, and got us more meat, more calories. Evolutionary forces favored humans (and their immediate ancestors) that were smart enough to do all of those things.

Once we banded together though, the situation became much more complicated. We were cooperating with other humans, our hunter-gatherer band pals, but we also needed to maximize how much of the food that each of us and our families received. This new focus on relational intelligence—the ability to quickly comprehend other people’s expressions and motives and to clearly and effectively advocate for our own needs—put another kind of pressure on our evolving brains, favoring even more intelligent humans, creating another wave of brain development (anthropologists would probably agree with the gist of what I’m saying but might also say that this language is too strong).

Boyd puts it this way:

Once the advantages of belonging to a hominid band had become overwhelming, the main pressure for our forebears became to secure their share of the resources obtained through the band’s efforts. They benefited by maximizing their own gains without alientating others, by allying with them strategically, outwitting them strategically, and resisting being outwitted in return. The complexity of such pressures seems to have caused the rapid growth in hominid brain size over the last two million years, and especially the development, as we will see, of an advanced theory of mind, a capacity to infer the beliefs, desires, and intentions of others, and a self-awareness that allows us to understand how others might infer our motives and react to our moves. (46)

So the tests that Jenny from Sports Night gave me were, it turns out, pretty good ones. First, she tested my tool use abilities. Then, she measured my response time to a language prompt, measuring the speed with which I satisfied another human being’s request. Both tasks are related to the evolution of human intelligence, more so than, say, watching a VHS tape called Mystery of the Aztecs, which is basically all we did in enrichment class.

Intelligence is the first of two major developments in human evolution that led, eventually, to storytelling, representational art, and fiction, according to Boyd.

Next up: the evolution of cooperation.

Gallery Note:

The gallery at the top is a series of great quotes from On the Origin of Stories that I made with Notegraphy. Shout out to the Mariana Funes for the suggestion!