Personality: An Ecosystems Perspective

(Welcome to the second installment of a three-part series on personality. Part 1 took the agent's perspective on personality development. Part 2, below, will take the systems perspective. And in part 3, we'll generalize 'personality' to explain all sorts of behavior, even in non-human entities like corporations.)

Last week I argued against the nature/nurture account of personality development. "Nature vs. nurture" exists largely due to the tools we have available to us and the data that's easy to measure — studies of twins reared apart, for example. But this is like the drunk looking for his lost keys under the street lamp. A policeman stops by. "Is this where you lost them?" he asks. "No," replies the drunk, "But the light is better here."

Similarly, it's easy to shine a light on nature vs. nurture, but that's not the best axis for understanding how personalities develop. It doesn't 'cleave nature at its joints.' We need to look elsewhere, even if the light isn't as bright.

So I presented an alternative model: prototype vs. socialization. I argued that the brain's personality mechanism exists to make lemonade out of lemons — that is, to assemble the best possible strategy for succeeding in life based on what we're given: a particular body, some particular (but tentative) cognitive traits, a particular physical environment, and a particular social environment.

Or in other words, personality is what happens when a prototype (i.e. a child) confronts the world. Nature and nurture are both responsible for building the prototype — it's a result of the genes interacting with the early environment (womb, early childhood, diseases, etc.). But the real molding of personality happens only after the prototype is released into the world.

All the learning and tweaking and (unconscious) strategizing that happens when the prototype interacts with its environment — that's the interesting part, i.e., figuring out how to deal with one's self and body in a world of other selves and bodies. I called this process socialization to emphasize the role of the social environment (even though the physical environment has some influence). And the learning itself is driven by simple behavioral reinforcement: do more of what works and less of what doesn't. In other words, we become what we are rewarded for.

To summarize:

Personality is what happens when you take a generic but very powerful reinforcement learning algorithm, attach it to an agent (with a body and some basic tendencies), and set it loose in a social ecosystem.

Today we're going to dig into the socialization process, giving it a richer explanatory structure using a few concepts from ecology.

The ecology of socialization

Ecology, as I've argued on a number of occasions, isn't just the study of organisms in the biosphere. It's a set of tools and a way of thinking that apply whenever there are independent agents competing with each other and interacting with their environment. The same tools that help us understand how species evolve within a niche can help us understand how employees grow within a company, how companies compete in the marketplace, and (as we'll see here) how children are socialized among their peers.

Central to the ecological toolkit is the concept of a niche. A niche is a subset of behavior-space that provides a certain set of incentives to an agent who tries to occupy it.

A niche is said to be wide if it's highly rewarding (i.e. supports a lot of agents) or narrow if it's only rewarding enough to support one or a few agents. A niche can also be more or less crowded, depending on how many agents are competing for the limited space/resources within the niche. And of course there are an infinite number of niches that aren't viable at all, but we mostly don't bother discussing them.

The parallels to personality development should be obvious. The human social world (and to some extent the physical world as well) is full of niches, some more rewarding than others. Here are just a few of the many niches available within a given social group:

Alpha, beta, supporter (this is a wide niche), mutineer, joker, loner, troop-rallyer, mediator, etc., etc.

And these are just the niches that have convenient names. In reality there are as many niches as there are people; everyone finds his or her unique niche.

The relationship between niche and personality is so strong, we could even use it as a definition:

Personality is an adaptation to a social niche.

Formally, a niche is a subset of behavior-space. If you recall, both strategies and personalities are also subsets of behavior-space. They're three ways of looking at the same thing. A niche refers to behaviors that are possible within a given setting, while strategies and personalities are the actual, concrete instantiations of those behaviors. Or to put it another way: a niche is the 'negative space' in the environment that gets 'filled in' by a specific strategy/personality.

Niches exist whether or not anyone steps in to fill them, but when they're empty, they exert an attractive force, pulling agents in by rewarding behaviors that are part of the niche.

Every class has its clown, because "class clown" is a strong, viable niche (even if it's not particularly wide) — a stable attractor in the social behavior-space of a classroom. If a class doesn't yet have its clown, someone will inevitably find that making a wisecrack is rewarded (with social approval in the form of laughter), and before you know it, he or she will be cracking wise at every opportunity.

But like I said, there are far more niches, which are far more nuanced, than just the ones we've learned to identify by name. "Alpha," for example, doesn't refer to a single niche, but rather a whole class of niches that happen to share a particular feature (being on top). There are many different types of "alpha" niches — leading by intimidation, leading by example, leading by wits and with humor, servant leadership, having an inherited titled (kingdoms etc.), leading with the support of the people, etc.

When it comes to personality, what's important is the fit between the niche and who you 'naturally' (albeit tentatively) are. A lot of personality development involves growing into a niche, but some niches fit better than others, so it's also important to find the right niche. This is where the body and basic cognitive tendencies come into play. There's a lot of variation among children (even before adolescence forces them to specialize even further), so it's important to find a niche that plays to one's unique strengths.

Ecology has a lot to say about finding and fitting into a niche. There are at least three processes involved, and you can see all of them at work in the development of personality:

Niche selection — searching for a good niche. When an adolescent leaves one social group and moves to another, for example, she's attempting to find a better niche for herself. For whatever reason, the old niche wasn't rewarding enough — too cramped, too small, too much competition — so she sets out for greener, more open fields. Maybe she'll find what she's looking for, or maybe she'll have to keep looking. There are clearly tradeoffs to be made between the known benefits of exploiting a given niche, and the potential benefits of finding a better one. I explored this in a lot more detail in an earlier essay on settling.

Niche adaptation — changing one's behavior to be more suited to a particular niche. Because we spend most of our lives 'in' a given niche (rather than searching for a new one), adaptation is happening all the time. We're constantly trying out new behaviors, learning which ones get rewarded and which get punished, and modifying our habits accordingly. But even though adaptation is happening all the time, we feel it most acutely when we take on new roles (e.g. at work, or in a new social setting), because that's when we experience the biggest mismatch between our habits and the behaviors that are rewarded by our niche. That's the steepest part of the learning curve.

Niche construction — reshaping one's niche to make it more rewarding. The hallmark of niche construction is conflict — a fight over some kind of territory. In the case of personality, it's a fight over 'territory' in behavior-space. By behaving in a certain way, I lay claim to those behaviors as part of my niche, and you can challenge my claim by attempting to punish me for it. If I win (not just the battle, but the war), I've successfully enlarged my niche.

Criticizing someone, for example, is a high-status move — and status is all about the occupation of space (whether physical or behavioral). When I criticize you, I'm claiming a position above you on the totem pole. If you accept my criticism — or even just my right to criticize you — you've ceded ground and I just enlarged my niche. If you fight back, then we have disputed territory on our hands. Maybe our conflict will escalate, maybe I'll give in, or maybe we'll retire and fight again another day.

On the necessity of niche construction

Niche construction doesn't always involve conflict, but however it's done, it's a political act. You can't change the size, shape, or incentives of your own niche without changing the size, shape, or incentives of other niches. So if you're hoping to avoid conflict, the best you can do is be subtle and clever in your efforts at niche construction. For example, you might invite a known ally into your social group, or steer the group toward activities that benefit you and away from those that don't.

Niche construction — especially in the form of fighting over territory — is an absolutely critical piece of the algorithm that learns a personality. Game theory tells us that you can't find an optimal strategy until you've pushed up against every boundary you can find; some lessons can only be learned the hard way.

George Stigler put it best:

If you never miss a plane, you're spending too much time at the airport.

By the same logic, if you never fight to enlarge your territory, you're living in too small a space. You can't spend your whole life within the boundaries other people set for you; you have to color outside the lines every now and then.

So that's what we all do. We push. Some people learn to be meek and avoid conflict — but only later in life. During the formative years of personality development, we're all pushing against each other, jostling and fighting and always trying to be as 'big' as possible. Every two-year-old knows how to do this: to push and test his parents' boundaries in new ways every day. And this goes on just as much outside the home as it does inside.

Predictions and retrodictions

The prototype/socialization/ecology model helps explain some facts that would otherwise be puzzling. Here are some of the more interesting ones.

Why peers are so important. Home life only goes so far in shaping a child's personality. The bulk of it gets forged in the child's social life outside the home — among his or her peers. Peers are important because they're our main competitors, collaborators, and sexual partners — the people we play social games with throughout our lives. Additionally, they're the best reference class for learning about our own strengths and weaknesses (whether we're ugly or beautiful, dull or clever, etc.). As Judith Rich Harris explains in No Two Alike, we can't learn these things from our family:

Being favored by a parent tells a child nothing that will be useful to her later on, but being given special treatment by many different people is informative. Being dominated by an older sibling conveys no useful information to a child, but being dominated by children of his own age is informative.

Why the teenage years are so important. It's no coincidence that personality is particularly volatile during adolescence — i.e., as the body finishes maturing. It would be counterproductive to allow personality to 'set' before puberty — before the final growth spurt and before secondary sex characteristics have developed. This doesn't mean childhood is unimportant, only that adolescence has the final say.

The high-school height premium. In a fascinating study, Nicola Persico and Andrew Postlewaite found that there's a correlation (among males) between height and salary. The natural explanation is that taller men are more dominant among their coworkers, which translates to better pay. But it's not quite so simple, because the correlation is even stronger if you go back and look at the men's height at 16 rather than their current height. Yes, employers are probably paying for dominance, but that dominance arises not from a man's current stature, but from his stature during the formative years of personality development.

Why stunningly gorgeous people tend to be vapid. Their beauty wins them everything they need; none of their other qualities are rewarded to the extent that they're rewarded for flaunting their looks. As a result, they don't need to bother developing other skills for succeeding in life — intelligence, humor, physical skills, etc. I'm not saying that all gorgeous people are vapid, but if you're gorgeous, you face fewer incentives to develop other qualities.

Why celebrities have crazy personalities. Celebrities live in a niche that gives them very little negative feedback. Their beauty and talents are so highly prized by society — and by all the people around them — that no one dares give them the same level of pushback that the rest of us experience on a daily/hourly basis. Relative to the rest of us, their personalities are shaped less by social feedback and more by a natural expression of who they are and what they desire. Part of the fun of watching celebrities is seeing what they can get away with.

This is also what happens to CEOs (who can e.g. get away with throwing tantrums), billionaires (who tend to become more eccentric than the rest of us), and anyone else with relatively unchecked power (e.g. North Korean dictators). Elected politicians, on the other hand, experience an extreme level of feedback from society. Some still manage to develop big personalities, but many retreat to bland likability in an effort to avoid offending anyone.

Originally published April 26, 2013.