MBTI and the Evolution of the Brain

Apr 16, 2021

This week, we’re finally going to pay off a debt from several weeks ago by looking at cognitive function pairs, while figuring out why the brain is designed in such a way that these pairs should be in apparent opposition to one another. Hoo boy.

So, we talked about the tension of opposites a few weeks back, now we can take it a step further. Why are functions pairs in opposition to one another?

The answer is, they’re not.

Well, at least they shouldn’t be. To understand this, we’re going to have to take it back a few million years.

I’ve long been interested in the triune brain theory. This a theory of how the brain has evolved. In a nutshell: we started out with a reptile brain: responsible for instinctual behaviours such as those involved in aggression, dominance, territoriality and ritual displays.

Then on top of that, we evolved a paleomammalian brain: responsible for feeding and behaviours related to reproducing and parenting.

Then on top of that, we evolved the neomammalian brain: this is regarded as the most recent step in the evolution of our brain, and is responsible for language, abstraction, planning and perception.

If we understand that the primary goal of humans at the most fundamental level is to survive and reproduce, from here we can begin to understand that each cognitive function has its own goal within that bigger picture (and suffice to say, from the triune brain, it’s not actually too difficult to join the dots and figure out where each function fits within the evolutionary structure of the brain while figuring out which goals the function pairs were looking to achieve, or which problems they were seeking to solve.):

We talked about introverted sensation (Si) last week and it’d be both reductivist and boring to carry on that theme in to this week by talking about Si as only serving the purpose of survival by wishing to stay in the cave, by the fire where it’s safe and warm. That would do an incredible disservice. It’s more interesting to look at the creative archetypal manifestations of Si and the purposes they serve. So, let’s start of by looking at astrology. Yes, astrology is a manifestation of Si and yes, there was a time where your life would have depended on astrology.

If someone is to tell me that my star sign is Leo, it means little to me. However, there was a point in our collective history where the position of the stars in the sky would have corresponded with important things like how much food was available on the ground and thus my potential for survival. And thus, the idea of Leo being associated with abundance is imprinted in our collective memory. Equally, I would go as far as to say that many of the most common archetypes found within religion are a result of Si and not Ni as many would be inclined to believe. One example being Jesus.

As I tweeted a few days back, Jesus is just the most recent guise for the Sun God: Apollo, Belenus, Helios. Jesus’ birth in the Christian calendar coincides with the winter solstice, which is the slow awakening of the sun. His death and resurrection being at the spring solstice: the run of the light. To put it in the most simplistic way imaginable: understanding the seasons and the importance of the sun is extremely advantageous and that is why themes such as these have been creatively implanted in our collective psyche.

From there, we have a platform for extraverted intuition. And in evolutionary terms, it shouldn’t be too difficult to figure out why a predilection for emergent possibilities is a handy tool to have. It’s all well and good sitting around the campfire telling stories about great sky gods, heroes of renown and great bountiful harvests from times of yore but wisdom alone isn’t going to bring about the next meal, let alone the next harvest. New possibilities have to be imagined. “What if instead of doing it that way, how about we try it this way instead?” New potential for life emerges, as do new stories, new gods and new heroes. For things to stay the same, everything must change.

Extraverted sensing (Se) and introverted intuition (Ni) can be viewed as the most primal functions. Se is attuned to the external environment and simply collects data. This is the function most suited for the job of detecting a sabre-tooth tiger emerging out of the long grass and quickly adapting to its surroundings in order to throw a spear (it is no coincidence that most elite sportsmen and women, in sports involving speed, skill and quick adaption are high stack Se users) or detecting a potential mate. It is perception of the most basic form. While introverted intuition (Ni) draws connections from the gathered data. See, it’s all well and good being able to detect an existential threat in your environment and quickly respond to it. But from that, you have to start making connections such as, “Well, if there’s one tiger in that area, I can picture there being other tigers too and I don’t like the image I have of myself getting my entrails torn out, due to only having one spear to throw.”

Now that we’ve got an idea of what’s going on with the perceiving functions, we can get an overview of the judging functions. Firstly, we’ll look at extraverted feeling (Fe) and introverted thinking (Ti). Both are located in the cerebral neocortex. So, in terms of the triune brain theory, that’s the neomammalian brain. And this gives us a good indication of we’re at. We’ve moved past hunter gatherer times and we’re now at a point in our evolution where we’re looking at doing things like agriculture and farming.

This is a huge leap forward for humanity. We’re at a point where we’ve realised that not only can we pool our resources as we’ve invariably always done, we can start making things far more efficient for ourselves. Which will have the net result of subsequently freeing up more brain power which can be used elsewhere.

As a species, our survival is reliant on other people, however, other people are also our competition for food, resources, mates. So, Fe is first and foremost about ensuring the tribe has the same collective values and everyone is on the same page. This is pretty important if you want to take a big societal leap forward. It’s a lot easier to start a big farm commune if everyone collectively understands how this benefits them as a group. This is the Fe side covered in a nutshell. However, you still require individuals with the technical knowledge and skills to put the plan into action. After all, it’s a lot easier for a group of people to go and round up a bunch of animals if someone is able to come up with ways to construct the right tools for the job and then figure out how to build a compound to put those animals in. The incentive here is to remain safely as part of the group. You get safety in numbers and get to benefit from the resources the group has collectively put together. Therefore, to stay as part of the group you must adhere to the group’s collective values. And if you don’t? Well, you get ostracised. Good luck going out into the wilderness and setting up an intricate engineering project on your own. Suffice to say, the threat of being cancelled isn’t a new phenomenon.

Finally, we can look at extraverted thinking (Te) and introverted feeling (Fi). We’re still in the exact same part of the brain and it’s indicative of the fact that there’s not an entirely dissimilar underlying logic at play. Nonetheless, we’ll explore the differences. Te is invariably more concerned with organising things rather than people, but the latter is certainly not something Te struggles with. On our hypothetical early human farming commune, we could easily see Te as managing the resources, if not the people but this isn’t a huge leap in terms of ability. So why should there be a difference? Why would we need Te and Fi (or vice versa) if Fe and Ti are more or less holding early humanity together, adequately?

I’d speculate that somewhere along the line, a new strategy became necessary and that was likely a result of things beginning to fragment. So what we’d be left with was a period of adaption where, say, threatening to ostracise people if they didn’t conform to collective values wasn’t enough. The problem would be one of pragmatism. As many managers can attest, you will at some point have a particularly difficult employee who you’d love to get rid of, but you simply can’t due to how utterly indispensable they are. So we, as a species, needed a new way to motivate people. And rather than collective values, we begin to see an emergence of individual values under the auspices of achieving larger collective goals.“If you do what I want, I’ll reward you with (insert whatever the individual covets).”

I’d hypothesise that in many respects we’re the victims of our own success. As we became increasingly efficient in terms of managing our resources at a societal scale—which in turn freed up more of the resource of the brain to focus on other avenues beyond that which ultimately amounted to survival and reproduction— we began to run into problems in terms of the differentiation of our cognitive functions. From here, I would argue that we started and continue to use our cognition to try and tackle problems far beyond what they were designed to do. And we’ve subsequently gotten ourselves into a bit of mess.

The Fifth Function

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