This is your brain on metaphors

A loyal mindblog reader has pointed me to an essay by one of my heroes, Robert Sapolsky, written for The Stone, a blog hosted by The New York Times which as a forum for contemporary philosophers. He discusses how the brain has evolved to link the literal and the metaphorical by duct-taping metaphors and symbols to whichever pre-existing brain areas provided the closest fit. The insula, for example, registers gustatory disgust.

Not only does the insula “do” sensory disgust; it does moral disgust as well. Because the two are so viscerally similar. When we evolved the capacity to be disgusted by moral failures, we didn’t evolve a new brain region to handle it. Instead, the insula expanded its portfolio.

...there’s a fancier, more recently evolved brain region in the frontal cortex called the anterior cingulate that’s involved in the subjective, evaluative response to pain...When humans evolved the ability to be wrenched with feeling the pain of others, where was it going to process it? It got crammed into the anterior cingulate. And thus it “does” both physical and psychic pain.

Sapolsky reviews a range of other studies showing how the brain links the literal and metaphorical, several of which have been the subjects of previous posts on this blog (cleanliness influencing moral judgements, holding a hot versus cold liquid influencing personality judgements, the weight of a resume influencing the judged gravity of a job applicant, etc.).

The viscera that can influence moral decision making and the brain’s confusion about the literalness of symbols can have enormous consequences. Part of the emotional contagion of the genocide of Tutsis in Rwanda arose from the fact that when militant Hutu propagandists called for the eradication of the Tutsi, they iconically referred to them as “cockroaches.” Get someone to the point where his insula activates at the mention of an entire people, and he’s primed to join the bloodletting.

And, an example of the sort in my recent post on resolving conflict:

But if the brain confusing reality and literalness with metaphor and symbol can have adverse consequences, the opposite can occur as well. At one juncture just before the birth of a free South Africa, Nelson Mandela entered secret negotiations with an Afrikaans general with death squad blood all over his hands, a man critical to the peace process because he led a large, well-armed Afrikaans resistance group. They met in Mandela’s house, the general anticipating tense negotiations across a conference table. Instead, Mandela led him to the warm, homey living room, sat beside him on a comfy couch, and spoke to him in Afrikaans. And the resistance melted away.

...Nelson Mandela was wrong when he advised, “Don’t talk to their minds; talk to their hearts.” He meant talk to their insulas and cingulate cortices and all those other confused brain regions, because that confusion could help make for a better world.