3 Things We Know About the Ancestral Environment
How the human world has changed — and why it matters
Posted Jun 22, 2018
The evolutionary approach to human behavior largely seeks to understand how psychological and behavioral processes would have provided our ancestors with survival and/or reproductive benefits under ancestral human conditions.
A common criticism of this approach to psychology focuses on the fact that since we do not have time machines, we cannot know what ancestral conditions were like — suggesting that a foundational feature of the field of evolutionary psychology is flawed.
Actually, based on various kinds of scholarship, including work by biological anthropologists, geologists, evolutionary biologists, geneticists, and cognitive scientists, there are several important features of the ancestral human environment that we can be certain about. Importantly, in fact, there are several specific features of ancestral environments that were certainly different from modern environments. An understanding of these environmental conditions, along with how they differ from our modern worlds, is key to understanding what it means to be human today.
Below are three substantial ways in which our modern environments differ from the ancestral conditions that surrounded human evolution.
1. All humans were hunters and gatherers.
Biological anthropologists have examined questions regarding the origins of agriculture in detail. According to all kinds of evidence, the agricultural revolution did not begin until about 9,000 BC - or about 11,000 years ago (see Bellwood, 2004). The advent of agriculture was a game changer, leading to what is often referred to as the Neolithic revolution. In short, once people figured out how to grow and domesticate their own food sources, they could stay put. And just like that, humans no longer had to be nomads who spent all day hunting and gathering and moving from place to place. Our diets changed dramatically. Our amount of average exercise changed dramatically. Our group sizes changed dramatically. Cities formed. These are things we know.
2. Ancestral humans did not have McDonald’s, Fortnite, or pornography.
Supernormal stimuli (see Tinbergen, 1953) are stimuli that represent extreme versions of stimuli that animals show evolved responses to. In studying a broad array of animal behaviors, renowned ethologist, Niko Tinbergen, discovered that many animals that are attracted to certain cues will respond more strongly to human-made, exaggerated versions of these cues. A herring gull chick that will peck at a mother’s beak that has a small red mark will peck even more strenuously at a human-made larger red patch — with even larger human-made red patches being even more likely to lead to pecking behaviors. The more the better!
Without exactly realizing it, humans in all kinds of industries have used technologies to create all kinds of supernormal stimuli. The reason is that supernormal stimuli sell. And such stimuli sell because our minds, which evolved under ancestral conditions in which the supernormal versions of these stimuli were absent, are like the minds of herring gull chicks — we evolved simple “more is better” algorithms when it comes to so many kinds of stimuli in our worlds.
We evolved a taste for foods that are high in sugars and fats because drought and famine common under ancestral conditions. So now McDonald’s is very popular around the world. You may have never thought about it before, but a Big Mac is a supernormal stimulus. And so are all highly addictive video games (such as Fortnite). And so is pornography. McDonald’s, Fortnite, and Playboy did not exist under the conditions of human evolution. This point is not equivocal.
3. Ancestral humans did not have cell phones.
When someone says to me that “evolutionary psychology is wrong because there is no way of really knowing what the ancient world was like for humans,” I will usually say, “Oh yeah — do you think that our ancestors had smart phones on the African savanna 200,000 years ago?!”
The fact is that people across the world are addicted to our cell phones and other devices — which are all based on extremely modern technology from an evolutionary perspective. A recent CNN poll found that 50 percent of teens in the U.S. report being addicted to their cell phones. And we all know that the other 50 percent are lying!
I was surprised during a recent visit to China, where I taught about 90 undergraduate students in the city of Chongqing, that the students there seemed to be just as addicted to their cell phones as the students here in New York are. And it’s not just young people these days. A few years ago I was proud to be one of the few adults I knew to not own a cell phone. I now own one and I probably check it at least 100 times a day, to be honest. (There, I said it!)
Cell phones are completely evolutionarily mismatched from communication mechanisms found in ancestral human conditions. They allow us to obtain social information in an immediate and large-scale manner. This fact is reinforcing, but it is also not exactly how social interactions worked under the conditions that surrounded human evolution.
And research on the psychological outcomes of being tied to your cell phone has a very clear result: It is not healthy for us (see Twenge, 2017).
Look, I know that we don’t have time machines — and I know that, to some extent, our understanding of ancestral human environments is guess work. But let’s be clear: There are definitely many specific things that we know about ancestral human environments. Further, we can be quite confident that there are many specific ways that our modern environments differ from those ancestral conditions. Ancestral humans did not live in cities, they did not eat Big Macs, they did not play Fortnite, and they did not have Snapchat. And all of these facts have substantial implications for human psychology. Next time someone tries to tell you that the evolutionary approach to psychology is off because we can’t really know what ancestral conditions were like, ask them if they think ancient people had iPhones and ate Chicken McNuggets.
Bellwood, Peter. (2004). First Farmers: The Origins of Agricultural Societies. Blackwell Publishers.
Tinbergen, N. 1953. The Herring Gull's World. London: Collins.
Twenge, J. (2017). Why Today’s Super-Connected Kids Are Growing Up Less Rebellious, More Tolerant, Less Happy--and Completely Unprepared for Adulthood--and What That Means for the Rest of Us. New York: Simon and Schuster.