How Nature Shapes Psychology - Left, Right, and Mother Nature

Sex, Power, and Partisanship: How Evolutionary Science Makes Sense of Our Political Divide - Hector A. Garcia 2019

How Nature Shapes Psychology
Left, Right, and Mother Nature

Every year something spectacular happens on the Serengeti, something that exemplifies the eternal and binding relationship between life on Earth and the natural environment. Following the nutrient-rich grasses brought to life by rolling, tidal rains, 1.5 million wildebeest—with countless zebra, impala, eland, and antelope in tow—sweep across the African plain to form the largest movement of land mammals on the planet. The unfathomable herd of horned, hooved, snorting, bleating wildebeest marches across the savanna like an unstoppable army, driven by an invisible, unswayable, instinctive force. Until they come to a river. For good reason, the onslaught halts here. Floating in wait beneath the muddy brown flow are one-thousand-pound crocodiles—green, coldblooded terror machines carried over from the age of dinosaurs, with spiked teeth, and jaws capable of 3,500-pounds-per-square-inch force (about the weight of a Volkswagen bug).

Understandably the wildebeest stop here, peer over the edge, snort, stamp in place, look nervously at one another, and then stare back into the muddy river. One can almost imagine one saying to another, “Well, I'm not going first; you go first…. No, I'm not going; you go,” and so on. Turning back is not an option—those grasses have already been eaten, or ground to dust under the hooves of the swarming millions. On the other side are stretching plains of fresh, green, lush grasses, so necessary for life. The clogging continues until finally something remarkable happens, as it has for many millions of years. Amid the indecision, one among them seems to make up its mind and say to itself, “Screw it, I'm going.” Several others follow, leaving a line of hesitators on the bank, waiting to see what happens next.

An important point that I wish to emphasize here is that the decision to surge ahead through that dangerous river is not completely random. The ones that go first tend, on average, to have an inborn predilection for taking the first step. This trait, which as shorthand we can call risk-taking, has its benefits. Those who make it across will have less competition for the lushest, most nutrient-rich grasses, as well as the freshest drinking water. However, you know what happens next. Submarined green monsters zero in, clamp down, and drag the intrepid gnus under, where they are drowned, twisted apart, and consumed.

Yet, some of these bold river-crossers make it to the other side and feast first on the greenest grasses and drink the freshest water. It's not hard to understand how this would have its survival advantages. Those born with traits coded for risk-taking probably reap the benefits for survival and reproduction as often as not in other ways besides access to the choicest greens. But why then aren't all gnus risk-takers? Because these same traits coding for risk-taking also land some wildebeest in the stomachs of crocodiles.

Back on the other end of the herd, queuing last in the rush across, are the lingerers. These wildebeest are less often food for crocodiles, but they also don't enjoy the freshest, most nutritious grasses, or any of the other perks of being spunky, and this is why all wildebeest aren't lingerers—because on average these gnus are likely to have poorer nutrition and in lean times may die of hunger or thirst more often than those at the spearhead. Notably, most of the wildebeest herd is somewhere in the middle.

What I hope to explain with this picture is how the environment shapes psychological traits and how those traits fall along what is known as the bell (or, natural) curve—in this case the most intrepid and the most hesitant wildebeest making up the tails of the curve. Now, population genetics among the wildebeest are obviously far more complex than what I have just described, and this explanation is more illustrative than scientific. However, there is a growing body of science to show that humans, like other creatures of the natural world, share similar basic predispositions to approach or avoid. It is not possible to fully understand human politics without understanding the ancient dangers of the natural world that shaped these modern-day inclinations. Before we explore what those dangers were for humans, we will first come to understand their outcome—our personality traits.