By Sarah Fishleder
The way we learn can determine not only our brains, but also the kinds of choices we make, from big to small.
You call THAT an elephant?
Eight graduate students sat down to play a drawing game. All of them got different colored pens. Six were part of a society, BlueLand, while two others were sent away to work in isolation.
BlueLand had a king, and his role was to lead his subjects in the act of drawing an elephant without directly telling them what to do. No description was given to the king, but instead he was told what he was to draw (i.e.: ‘draw a blue elephant). This served as a fitness advantage.
The remaining two graduate students were taken into the hallway and were told to draw the following creature. The description was that the creature had huge feet, giant toenails, wrinkly ankles, short, thick legs, horns coming out of its head with a long, giant nose that takes up half its face, enormous ears, a huge round body, and a short tail with a brush at the end of it. You can see the red and black outcomes just above.
The king drew a blue elephant himself. Then, without saying anything, he showed it to the people in his kingdom. Although the group members were confused, almost every subject ultimately decided that the king was the only one who had any idea about was going on at all. They followed their leader’s example, drawing the elephant with a blue pen. You can see that BlueLand’s drawings look—more or less—like the same elephants. This shows how ideas can be transferred, although not necessarily identically.
The members who accurately drew a blue elephant received the prize that is treasured universally by all graduate students. That’s right: ramen noodles.
I know what you are thinking: “Why make fun of grad students this way, kinda like Bart Simpson does in this clip? Who cares about their drawings, and what does this have to do with either learning or human neurological development? Someone get me a cocktail!”
BELIEVE ME, I thought the same thing. But the truth is, the way we learn — even something as simple as drawing an elephant — shapes our brains, and determines the choices we make. This blog post will use a cultural evolution approach, in conjunction with neuroanthropology, to examine the connection between the way we learn and our daily decisions and actions.
1. How we learn shapes how we make decisions
The elephant drawing game shows that ideas can be transferred, but not necessarily as identical replicas. The fact that ideas are transmitted imperfectly leads to one big question: after innumerable mistaken copies, wouldn’t any idea completely lose its original form? Thus, any functional value for survival would be lost. For example, a ramen noodle recipe copied imperfectly would end up making some kind of revolting mush after enough iterations. Not like it is when it is actually cooked right.
Of course, we know that doesn’t happen. People ARE able to successfully share ideas and learn from the group with a relative degree of accuracy. After all, the blue kingdom does have—more or less—a bunch of blue elephants.
In their foundational paper on cultural evolution, Henrich and Boyd (2002) discuss how the integrity of an idea is protected, even if the idea is not spread perfectly. One means is the concept of conformist bias, where people will behave in a similar form as those around them. Even if they learned the idea in a different way, they will choose to do what everyone else is doing. Thus, even with imperfect transmission of ideas, the end results are usually very similar within a population. This allows the idea to remain beneficial, and not get corrupted with continual mis-copies.
A similar concept, prestige biased transmission, works synergistically with conformist bias in cultural evolution theory. Individuals will adopt the habits of those with the highest rank, based on the unconscious assumption that the prestigious individual’s success has a legitimate foundation in higher fitness ability. Additionally, less-than-perfect inheritance requires stronger selective pressures to keep it in line.
In the case of graduate kingdom BlueLand, members all had imperfect, but reasonably-drawn elephants. However, those who were socially isolated ended up with strange creatures as seen through beer goggles. Cultural evolution explains this outcome by arguing that in groups, we tend to imitate higher-ranked individuals and do what the rest of our peers do.
2. Social learning is a biological neural capacity of humans
This shows that fundamentally, the consistent elephant shape required learning from others. However, in order for the people to share ideas, they have to have the neurological ability to do so (Richerson & Boyd 2005, Boyd, Richerson & Henrich 2011). Imitation is the replication of observed behaviors, and is argued by Richardson and Boyd to be the essential mechanism for social learning and development. Imitation differs from genuine learning, in that it requires fewer resources with the tradeoff of a less accurate understanding of the advantageous behavior.
There is a time and place for both types of learning. When simply copying someone gets the job done (like peeking on your neighbor during the chemistry exam), imitators have higher fitness because they did not have to spend the extra energy actually learning: they simply imitated. However, when the imitation may not cut it (like when your neighbor’s test is on art history and yours is a chemistry exam), knowing the material is the more advantageous choice. Of course, that’s just an example. I mean, it’s not like that ever actually happened to me. That’s for sure.
Boyd, Richerson & Henrich (2011) contend that these types of learning end up benefiting the entire population because it allows people to learn selectively. No, I don’t mean how I passed Driver’s Ed. I mean that people can choose to spend more energy acquiring the real skill when accuracy is necessary, and simply copy others who seem to have it figured out when slight inaccuracy is sufficient.
Ultimately, an equilibrium of these learning strategies organically forms within each environment. The authors argued that this model allows for small, cheap evolutions that decrease overall learning cost. Further, by distinguishing the most prestigious (fittest) teachers, learners have the surplus energy to recombine the best ideas into more complex ones (like FourLoko, amiright?!). This allows for a large fitness gain with little cost, if you know what I mean.
The term for how a culture retains its past and effectively passes it to future generations is called the ratchet effect. This, Tomasello (1999) bravely typed, is also the primordium of culture, as it is the means by which populations begin and maintain traditions. Through niche construction, this ratchet effect can lead to new abilities for humans to do neuro-cultivation.
Now I know what you are thinking: “Where the hell is my cocktail? And how the frak can a single force really explain so much of human development?” TRUST ME, I get it. Now take it easy.
Caldwell & Millen (2009) devised a controlled experiment with paper airplanes to test how collective knowledge was accumulated. They created “micro-populations” where each group was tasked with creating a paper airplane that could go the farthest. Participants worked in a chain of 10, one after the other. Different controls of social information were used, including the opportunity to observe making paper airplanes (imitation), opportunity to inspect completed planes that had been flown (emulation), and opportunities to be taught directly by previous flyers (teaching). Experiments giving exposure to every combination of the three kinds of information were undertaken. All types of social learning showed a cumulative result, with the last fliers consistently having better planes than the first fliers. This supports the notion that multiple forces can contribute to cumulative cultural learning.
3. Genes and culture co-evolved (AKA: Dual inheritance theory. AKA: DIT)
The concept that genes and culture co-evolved is also known as Dual Inheritance Theory (DIT). Cultural traits alter the environment, which houses genetic selection. A common example of this biosocial development is that the human ability to digest lactose evolved at the same time as cultural adoptions of dairy agriculture. That is, as the cultural knowledge of dairy farming increased, the biological ability to digest dairy was also selected for in that population. The same thing happened related to the brain: as culture adapted, genetic selection caused a development of neural capacities for the transmission of social knowledge (see point 1). This intersection of genes, brains, and culture is beginning to be explored by cultural neuroscience.
By necessity, cultural selective forces must be much stronger than biological selective forces to have an effect. Take this sign in the 2014 Olympics:
It is common knowledge that Canada has a much stronger hockey culture than the US. And guess who still has Beiber?
Sperber (2000) contends that attractors are culturally-shaped ways of thinking that dictate choices. Henrich and Boyd (2002) argue that selective forces affect which attractors are present in a particular cultural context. Cultural selective forces determine the presence of those attractors, thereby shaping what decisions people make. Similar but not identical to genetics, culture faces certain pressures for change.
Richerson and Boyd name two kinds of forces, including decision-making and natural selection. Decision-making forces are akin to the attractors mentioned, and can be thought of as the psychological process of the actor, which influences the cultural trait. It is the thought process that goes into choosing the blue pen in the elephant drawing game, or how we all think about it and choose to hate Nickelback. These forces come from social pressures, traditions or cultural practice. Natural selection, Richerson and Boyd argue, selected for the human habit of learning from the most prestigious, and conforming to the methods of the horde.
Natural selection, however, does not fit inside the minds of the individual, but rather the population. The ultimate question of why cultural traits spread and proliferate, and why one trait is held above another is still outstanding. Boyd and Richardson’s model doesn’t exactly address this. Their model shows that natural selection enabled cultural learning and shapes how people choose (not why they choose). In other words, it is more focused on how social learning fits into the general evolutionary landscape.
It does not address the details why particular changes are wrought, which may be what is of direct value to social scientists. The real question is: what exactly is it about Nickelback that the culture rejects? Lewens (2009, 2010) argues that population thinking may fill this gap. That is, if researchers have appropriate insights into the group of minds, those researchers may gain insight into the forces that cause individuals to adopt one idea over another.
However, departing too far from traditional Darwinian models, at some point, makes the term ‘evolution’ somewhat asinine. How can it be Darwinian with only population thinking and no natural selection or actual evolution? Houkes (2012) argues that Lewen’s emphasis on population thinking crosses this line.
In another keyboard battle, Houkes argues for the necessary inclusion of natural selection of cultural items into dual-inheritance theory. Applying natural selection to cultural items in a DIT context includes a variety of genetic and cultural processes to explain a trait. It also acknowledges that maladaptive traits may be selected for, which an entirely population-based approach may be flawed in addressing (Read 2006). And we all know there’s some mal-adaption out there, in some populations in particular. (All we need to do is look outside and see how many men wear skinny jeans. Amiright??) But the bottom line is that there is a need to acknowledge there are several forces, both biological and social, that shape traits and behavior, and many of these traits are selected for over time.
4. The inevitable reality of maladaptive practices
Humans possess the power of cumulative cultural evolution, and therefore unfathomable innovation. They can and will learn cultural habits, even if they would never have thought of doing the action on their own.
However, there is a flipside to this incredible potential. This leaves the possibility that they will adopt any behavior, regardless of how much sense it makes, as long as the knowledge is transmitted in a way that conforms to the way the individual learns.
Think again about those stupid skinny jeans. Or of how my hair looked in high school (OK, stop thinking of that one now). Or how drug use can bring together group habits and individual learning in patterns of excess.
Furthermore, biases that have minute effects on the decision-making of the individual can be amplified exponentially across generations and repetitions (Beppu & Griffins 2009). Indiscriminate imitation of high-status individuals may also lead to a selection of certain maladaptive behaviors, particularly when those behaviors involve high-risk and high returns (Henrich & Broesch 2011). This means that while a single person may make a slightly maladaptive decision (enjoying that cocktail); down the line, others through amplified social learning and high-status behavior models may make a really really maladaptive decision (enjoying those twelve cocktails).
And so, that is why a dedicated graduate student — perhaps one writing about neuroanthropology and cultural evolution — might end up spending her spring break in a maladaptive way (perhaps testing the fitness of ramen against vodka in Miami). Spring break might be all about amplified social learning. And that is also why doing so is simply not her fault. It is not only in her biology. She learned complex behaviors from those around her, particularly those in leadership or teaching positions. Those prestige people. Perhaps, then, the real responsibility lies in professors at her grad school. The ones who got her into this cultural evolution thing in the first place…
So….now that you know whose fault it really is that my term paper is late, how about that extension?
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