Thinking Fast and Evolution

I have written in the past about how I think I probably put too much emphasis on evolutionary biology, especially considering brains, going all the way back to when our human ancestors liven in small tribes as hunter-gatherers. Perhaps it is because I look for it more than others, but I feel as though characteristics and traits that served us well during that time, still influence much of how we behave and respond to the world today. Sometimes the effects are insignificant, but sometimes I believe they do matter, and sometimes I believe they drive negative outcomes or behaviors that are maladapted to today’s world.


As I have begun writing about Daniel Kahneman’s research as presented in his book Thinking Fast and Slow, I have generally given System 1, or what Kahneman describes as our quick, automatic, and reactive part of our brain, a bad rep. But the reality is that it serves an important purpose, and likely served an especially important role over the course of human evolution, getting us to the place we are at today. Knowing that I tend to weigh our evolutionary past heavily (and perhaps too heavily), it is not surprising to me that I view System 1 as an important piece of how we got to where we are, even if System 1 is easy to pick on in our current world.




Anyone who has had to remember a couple of phone numbers without the benefit of being able to write them down or save them immediately, and anyone who has had to remember more words than Person, Woman, Man, Camera, TV, knows that we feel super rushed when we are suddenly given something important to hold in our working memory. We try to do what we can as quickly as possible to get the information out of our head, stored someplace other than our working memory. We feel rushed to complete the task to ease our cognitive load. Why would our brains work this way? Why would it be that we become so rushed when we have something meaningful that we need to hold in our mind?


The answer, as I view it, might go back to our hunter-gatherer ancestors. They mostly needed System 1. They had to react quickly to a noise that could be a dangerous predator. They had to move fast and on instinct to successfully take down dinner. There were not as many things that required deep focus, and the things that required deep focus were not dense academic journal articles, or spreadsheets, or PowerPoints, or a guy with a clip-board asking you to count backward from 200 by 13. You don’t have to worry about pop-ups or advertisements when you are skinning an animal, grinding seeds, or doing some type of work with your hands in a non-digital world. You didn’t have phone numbers to remember and you were not heading into a business meeting with four people you just met, whose names you needed to memorize as quick and fluidly as possible.


Slow thinking developed for people who had time for slow thinking. Fast thinking developed when survival was on the line. Today, the slow thinking might be more likely to help us survive than our fast thinking, presuming we don’t have dangerous drives to work each day and are eating safely prepared foods. Slow thinking is a greater advantage for us today, but we also live in a world where slow thinking is still difficult because we have packed more distractions into our environments. We have literally moved ourselves out of environments for which our brains are optimized by evolution, and this has created the challenges and conflicts we face with System 1 and System 2 in our daily lives and in the work we do.

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