The Olfactory Lives of Primates
Robert M. Sapolsky
Dear Chris,
I’m sorry you couldn’t make it to Brad and Caitland’s wedding. It was pretty good. The beginning dragged—the usual, everyone standing around, sniffing each other’s breath, figuring out who was from Caitland’s family, who from Brad’s. You could see people getting confused by Jessica, Caitland’s niece, the one who’s adopted.
At one point, this very attractive second cousin of Brad’s came up and sniffed my butt. Okay, I’ll admit it, it made my day. Then these two drunk guys from Caitland’s office got into this pissing contest, completely soaked a table-cloth doing it. I don’t know why they bothered—one of the guys had no testes, and he was terrified of the other guy—majorly acrid sweat.
Totally poignant with Hugh, Caitland’s dad. She didn’t think he’d last for the wedding. You could smell the cancer from across the room. I’ve always liked the guy.
One really funny thing—Caitland’s two sisters were both ovulating (it occurred to me that Brad had done that to them, which would have been really crappy of him), and they kept sniffing Tom’s crotch. They were trying to make it seem like this big joke, but it was obvious that they were, like, totally serious. Lame.
Scientists are capable of being as childish as anyone else, and fights often erupt over what name to give to some new discovery. This happened in the middle of the last century and concerned the name for a part of the brain. Deep in the brain’s underbelly, far from that gleaming cortex doing string theory physics, is this interconnected cluster of ancient regions, like the amygdala, hippocampus, and hypothalamus. The old guard of neuroscience had long called this network the rhinencephalon—“nose brain.” This made sense. In a rat, there’s this gigantic mass of brain cells that detects odors, and it funnels all that olfactory information, by way of cable-like “projections,” into that amygdala/hippocampus/hypothalamus network. Meanwhile, a bunch of young Turk neuroscientists ignored this rhinencephalon label. They were analyzing what the amygdala, hippocampus, etc., actually did. For example, what behavioral changes would occur if one of those regions was damaged? And they were finding some very interesting effects—changes in sexual or aggressive or maternal behavior. These folks concluded that this network was about emotion (and for reasons I’ve never figured out, they called this network the “limbic” part of the brain).
Rhinencephalon or limbic system? Smell or emotion? Coke or Pepsi? After factional violence that left thousands dead, a kumbaya-esque solution became obvious. For your typical mammal, there was no conflict—emotions equal odors. Sexual, aggressive, or maternal behavior never occurs outside the context of olfaction.
