Editor's Note: (Robert Sapolsky is a professor of biology, neurology and neurosurgery at Stanford University. He is also the author of "Behave: The Biology of Humans at Our Best and Worst." The opinions expressed in this commentary are his own. View more opinion articles on CNN.)
(CNN) Life is full of decisions. Stop to help that person? Buy that house? Sell those stocks? See what it's like to go over Niagara Falls in a barrel? We constantly weigh costs and benefits with thought experiments to imagine what the consequences of different choices might be, and emotion experiments to imagine how different outcomes would feel. All so that when we come to one of those junctures in life, we won't be haunted by having made the wrong choice between a Coke or Pepsi.
The coronavirus has placed us at a more consequential juncture that demands loads of important decisions. And this makes relevant a crucial neurobiological factor -- during times of stress, we tend to make lousy decisions.
People typically think of the parts of the brain that specialize in cognition and rationality (the cortex), and the parts mediating emotion (the limbic system), as completely separate departments. That's totally wrong. Instead, there's endless cross-talk between the two regions. The easy version of this is that your cortex regulates your limbic system -- picture your rational, sensible cortex racing to the limbic system to hector, "I wouldn't do that if I were you," hopefully convincing it not to do something idiotic. But it turns out that the limbic system influences the cortex as well.
This is not where we should get Mr. Spock-ish, lamenting how we'd be so much better off in our decision-making if our emotions played no role. Damage the ability of the limbic system to talk to the cortex and you get what we'd almost universally view as bad decisions. People with brain damage can barely make decisions, lacking a "gut feeling" for what's right. Moreover, their decisions are unrecognizably utilitarian; they have no emotional conflict in choosing to advocate sacrificing the life of a stranger (or, equally so, a loved one) in order to save five others. This is someone who, when being introduced to a stranger, would say, "Good to meet you, I see that you are really overweight."
In other words, when it comes to making decisions, the balancing act between cognition and emotion is pretty complex.
So, what happens when something stressful like a viral pandemic comes along? Typically, we feel stressed (and become more at risk for stress-related diseases) if we lack control, predictability, outlets for our frustrations, or social support. Our present crisis evokes all those. Thanks to lies, contradictions, and a lack of transparency from the White House, it's clear that we're getting some critical information -- like Trump's statement that "anyone who wants a test can get a test" -- that is not true. The most informed medical experts have to repeatedly answer questions with the wildly unsettling fact, "We just don't know yet." And in this time, when we need social support the most, the crucially important catchphrase has become "social distancing."
Thus, we're stressed as hell, and this is precisely when decisions get bad. This is understood on the nuts-and-bolts level in the brain. The most rational decision-making part of your cortex is the pre-frontal cortex (PFC), while the most frothing-at-the-mouth emotional part of your limbic system is arguably the amygdala, a region central to fear, anxiety and aggression. During prolonged stress, glucocorticoids, a class of stress hormones causes the PFC to become sluggish, less capable of sending a "let's not do something hasty" signal to the amygdala. Meanwhile, those same stress hormones make the amygdala more active, dominating the PFC and its decision-making process.
Extensive research has explored the consequences of this skewed neurobiology, showing that stress distorts our decisions in consistent ways. One is that we become more impulsive and less reflective (a pattern also shown in monkeys).
We end up having tunnel vision when it comes to making choices and it becomes harder to consider extraneous factors that may actually not be extraneous, or harder to factor future consequences into present considerations.
Another well understood consequence is that our decisions become more habitual and automatic. We fall back into a usual solution, and instead of trying something different when it doesn't work, the pull is to stick with the usual, but go at it more often, louder, or faster, assuming that it's got to work at some point.
There are unpalatable social changes as well when we are stressed. We're more likely to deal with frustration using a solution entrenched among primates -- taking it out on someone smaller. We are more likely to perceive neutral stimuli as threatening, and individuals prone towards aggression become even more so. And our decision-making narrows in another sense, in that we contract our circle of who counts as "us," and who merits empathy and consideration. Our moral decisions become more egoistic
Amid these neurobiological tendencies, we each face key decisions during this pandemic. Should I react as if we're all going to die? Should I run like a headless chicken to buy and hoard three years of dental floss sticks? Am I willing to make radical, upending changes in my life for the common good? Will I fall for a rumor and promptly pass it on, or succumb to the temptation of scapegoating amid the fear?
We face these challenges at the worst possible time. For three years, we've had a leader who dismisses unwelcome fact as fake. The US president is someone who glories in proud ignorance and rejects the World Health Organization's reported coronavirus death rate by saying, "I think the 3.4% is really a false number -- and this is just my hunch." He has made a virtue of narcissism and selfishness. And he has replaced decency with a moral system that reflexively targets the weak and vulnerable. He is a leader who has turned the most destructive imbalances between the limbic system and cortex into a national agenda.
We can't change the basic workings of our stressed brains. But we can be on guard against the worst tendencies our brains generate at such times. We must.