Christopher Shea writing in The Chronicle of Higher Education reviews Patricia S. Churchland's new book, Braintrust: What Neuroscience Tells Us About Morality (Princeton University Press)
Patricia S. Churchland, the philosopher and neuroscientist, is sitting at a cafe on the Upper West Side, explaining the vacuousness, as she sees it, of a vast swath of contemporary moral philosophy. "I have long been interested in the origins of values," she says, the day after lecturing on that topic at the nearby American Museum of Natural History. "But I would read contemporary ethicists and just feel very unsatisfied. It was like I couldn't see how to tether any of it to the hard and fast. I couldn't see how it had anything to do with evolutionary biology, which it has to do, and I couldn't see how to attach it to the brain."
For people familiar with Churchland's work over the past four decades, her desire to bring the brain into the discussion will come as no surprise: She has long made the case that philosophers must take account of neuroscience in their investigations.
While Churchland's intellectual opponents over the years have suggested that you can understand the "software" of thinking, independently of the "hardware"—the brain structure and neuronal firings—that produced it, she has responded that this metaphor doesn't work with the brain: Hardware and software are intertwined to such an extent that all philosophy must be "neurophilosophy." There's no other way.
....she is taking her perspective into fresh terrain: ethics. And the story she tells about morality is, as you'd expect, heavily biological, emphasizing the role of the peptide oxytocin, as well as related neurochemicals.
Oxytocin's primary purpose appears to be in solidifying the bond between mother and infant, but Churchland argues—drawing on the work of biologists—that there are significant spillover effects: Bonds of empathy lubricated by oxytocin expand to include, first, more distant kin and then other members of one's in-group. (Another neurochemical, aregenine vasopressin, plays a related role, as do endogenous opiates, which reinforce the appeal of cooperation by making it feel good.)
From there, culture and society begin to make their presence felt, shaping larger moral systems: tit-for-tat retaliation helps keep freeloaders and abusers of empathic understanding in line. Adults pass along the rules for acceptable behavior—which is not to say "just" behavior, in any transcendent sense—to their children. Institutional structures arise to enforce norms among strangers within a culture, who can't be expected to automatically trust each other.
Recognizing our continuity with a specific species of animal was a turning point in her thinking about morality, in recognizing that it could be tied to the hard and fast. "It all changed when I learned about the prairie voles," she says—surely not a phrase John Rawls ever uttered.
She told the story at the natural-history museum, in late March. Montane voles and prairie voles are so similar "that naifs like me can't tell them apart," she told a standing-room-only audience (younger and hipper than the museum's usual patrons—the word "neuroscience" these days is like catnip). But prairie voles mate for life, and montane voles do not. Among prairie voles, the males not only share parenting duties, they will even lick and nurture pups that aren't their own. By contrast, male montane voles do not actively parent even their own offspring. What accounts for the difference? Researchers have found that the prairie voles, the sociable ones, have greater numbers of oxytocin receptors in certain regions of the brain. (And prairie voles that have had their oxytocin receptors blocked will not pair-bond.)
Read more about Churchland's work on the brain, neuroscience, biology and ethics here