Social Brain Hypothesis

The California Redwoods are amazing trees. They stand taller than any other tree, scraping at the sky as they compete among each other for sunlight. The trees can be packed together in a dense manner, all competing for the same light, all pulling massive amounts of water from the ground up enormous heights. What is interesting, however, is that the redwoods are geographically isolated, not stretching out across huge swaths of the continent, but contained within a fairly narrow region. They don’t compete against other species and spread, but mostly compete for sunlight, water, and resources among themselves.


In The Elephant in the Brain, Kevin Simler and Robin Hanson introduce the redwoods as a way to talk about the Social Brain Hypothesis in humans. The idea is that our brilliant brains developed so that we could compete against each other, not because our brains really helped us outsmart lions or obtain more resources than other animals. The authors write,


“The earliest Homo Sapiens lived in small, tight-knit bands of 20 to 50 individuals. These bands were our “groves” or “forests,” in which we competed not for sunlight, but for resources more befitting a primate: food, sex, territory, social status. And we had to earn these things, in part, by outwitting and outshining our rivals.

    This is what’s known in the literature as the social brain hypothesis, or sometimes the Machiavellian intelligence hypothesis. It’s the idea that our ancestors got smart primarily in order to compete against each other in a variety of social and political scenarios.”


I find this super interesting because in many ways we are still fighting among each other as if we were part of a small band of 20 to 50 individuals. We live in a world where food is relatively bountiful (for many but certainly not all) in the United States. We live in a world of online dating where finding a mate is more open to more people. Our “territory” today can be more private than ever and online niche communities can give us a new sense of social status that we could not have obtained in the past if we did not conform to the small groups of our high school, family, or work.


We seem to be in a place where we can let go of the pressures that the social brain hypothesis put on our early ancestors, but I don’t see people shedding those pressures very often. We can look at what has driven our species to behave the way we do and see that we don’t need to compete in the same way. We can recognize the great possibilities available to us and move in our own direction, but so often we chose to just show off and do more to impress others as if we still lived in small tribal bands. Rather than branching out, we seem to often retreat back to a group of 20 to 50 and compete internally in a way that wastes resources on our own selfish motives. I think that we should talk more openly about the social brain hypothesis and the ideas that Hanson and Simler present so that we can have a real discussion about how we move forward without pushing everyone to compete for things that we should be able to provide openly with new systems and organizations.


Humans will always be competing against each other in one way or another, but I think we are at a point where we can begin to decrease our competition. Our societies are at a point where we can be more constructive and inclusive if we can decide that we don’t need to participate in so many of the competitions that drive the world today and ruin so many of our lives. Changes along these lines would probably encourage us to live in smaller homes, live in a more community focused way, show off less, and help each other more. How we get there and give up some of this competitive nature I am not sure, but I think that we need to move in this direction to act as a global species and solve major problems such as climate change.

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