Quirks & Quarks

Why our brains take metaphors literally with deadly results

Author Dr. Robert Sapolsky talks about the human brain's capacity to handle metaphors of violence and peace.
When the late South African President Nelson Mandela wore the team logo of the National Afrikaans team, it was an unbelievably powerful symbol, says author Dr. Robert Sapolsky. (Lefty Shivambu/Gallo Images/Getty )

Why do we do the things we do, say pull the trigger, or reach out to stroke someone's arm to comfort? Dr. Robert Sapolsky tackles such questions from multiple angles in his book, Behave: The Biology of Humans at Our Best and Worst.

Sapolsky is a professor of biology and neurology at Stanford University in California, and a recipient of a MacArthur Foundation genius grant.

He's spent much of his career studying a troop of baboons in Kenya. He's deeply interested in what animals reveal about evolutionary biology … as well as what he calls our species' problems with violence. For instance, humans create world destroying weapons, commit mass rape, and exert subtler forms of violence, like being passive/aggressive. 

Sapolsky speaks to CBC Radio Quirks & Quarks host Bob McDonald about the human brain's capacity to handle metaphors of violence and peace.

This transcript has been edited for length and clarity.

BM:  History is filled with examples of leaders using inflammatory rhetoric to incite violence. I'm curious about the peace time. You see the same connection between metaphor and violence when the scale is smaller?

RS: Absolutely. … We don't figure out who's one of "us" and who's one of "them" by smelling their pheromones the way a hamster might. We think about it and thus we're subject to being manipulated and how we think and pseudospeciation is this process by which we are propagandized into thinking that they are so different they hardly even count as human. The flip side is pseudokinship, when we are manipulated into feeling more related to someone than we actually are.

What's the classic example? Every good aspect of military training for millennia has involved turning a bunch of strangers into a "Band of Brothers." Everything about military training is to make you feel so connected to the guy next to you in the middle of some firefight that you're willing to give up the ultimate in order to save that person. Over and over what we do is at times where we want to be drawn closer post revolution, everyone addresses each other as brother and sister. You suddenly switch the grammar that you use for the familial terms in your language. So for better or worse we are constantly being sort of pulled one way or the other in terms of how similar or how different people feel to us.

When we're disgusted by some appalling act, we truly are feeling a bad taste in our mouth and feeling sick to our stomachs and feeling queasy and that gives an enormous power.- Dr. Robert Sapolsky

BM: Well you do mention in the book about how Nelson Mandela was an example of that where he actually learned the language of his captors to negotiate with them later.

RS: And not just sort of learning Afrikaans for the negotiation but to understand them and even more importantly he apparently spent forever with the correct conviction that someday he was going to be leading a peaceful post-apartheid multiracial society. And he needed to know the symbols and the visceral responses of everybody there. And of course the most famous example like you can't even contemplate without getting practically teary is Nelson Mandela and embracing rugby, South African Afrikaans' sort of emblematic sport, and him appearing there wearing the team logo of the National Afrikaans team. That was an unbelievably powerful symbol. And when that rugby team then lined up [with] all these white guys singing the ANC national anthem, an equally powerful symbol coming back in the other direction.

Neurons we use for metaphors also pop up in other species on the all-star team of social complexity, such as dolphins. (Steve Gonzales/Houston Chronicle/Associated Press)

BM: You ask a question in your book why do we have trouble remembering that metaphors aren't literal? What's going on in our brains there?

RS: There's this part of the brain for example called the insular cortex. And in any normal, boring mammal out there what it does is tell you that was a disgusting rancid taste and it triggers reflexes. Your gut heaves, you reflexively spit out the rotten food. It's a great thing for keeping you from like poisoning yourself with toxic food. And then in humans you contemplate the Rwandan genocide. And remarkably it's the same exact neurons that activate and thus this metaphor is not so metaphorical at that moment because your gut is indeed getting messages suggesting that it start feeling queasy.

(Penguin Press)

Our body turns those metaphors into very literal states and that's where they get their power from. When we're disgusted by some appalling act, we truly are feeling a bad taste in our mouth and feeling sick to our stomachs and feeling queasy and that gives an enormous power. For better or worse.

BM: What intrigues you about what you call our unique neurons in the brain that we share with evolution's Mensa club, the other apes, elephants, and cetaceans like whales, dolphins and porpoises?

RS: These are these neurons called von Economo neurons and people discovered them a while back in the human frontal cortex. And this was hugely exciting because the human brain isn't the human brain because we've invented new types of neurons and new types of neurotransmitters. For the most part you know where we get our specialness from is just the sheer quantity of neurons. But this turned out to be arguably the first class of neurons that were unique to humans. Oh my God, that is so interesting. Even more interesting: the parts of the brain they were exclusively found in [were] that insular cortex with moral disgust, something called the anterior cingulate, central to empathy, feeling somebody else's pain.

Our body turns metaphors into literal states, says Dr. Robert Sapolsky. (L.A. Cicero/Stanford University)

These are neurons that are just up to their ears in human-specific metaphor. But then as you say people looked and they pop up in some other species and it's like an all-star team of social complexity, other primates, whales, dolphins, elephants and all the species out there that are doing the most complex things socially seem to have these neurons and people are still trying to figure out exactly what they're doing.

BM: Whether or not they abstract like we do?

RS: Yup. We're probably not the only symbolic species, but anything in any other species is just the first rudiments.