Dear reader,
Chickens are known for their pecking order, and American economists are known for their ranking obsessions, but it’s male mice who have perhaps the most brutally enforced linear dominance hierarchies. Alpha Mouse bites Beta Mouse; Alpha Mouse and Beta Mouse bite Gamma Mouse, and so it goes, all the way down the line. Revolutions are rare and swiftly resolved.
In addition to biting his subordinates, Alpha Mouse also pisses everywhere, marking his territory. Mice burrow underground, but they must come up for sustenance, and the areas around the tunnel openings are prized territories, access to which is regulated by status. Alpha Mice also dominate access to mates. As with humans boarding an aircraft, position in the social hierarchy determines who gets to go first through a portal.
All this biting and pissing and fucking is time-consuming and metabolically costly. Alpha Mouse doesn’t sleep much, and he has to keep eating and drinking. Pissing, after all, requires drinking, and drinking requires thirst. When a mouse ascends to Alpha, he shows rapid changes in patterns of gene expression in his hypothalamus, a part of his brain that regulates hormones and basic physiological drives. More thirst, more appetite, less sleep, more testosterone, more sperm, more urinary proteins, better spatial cognition. Faster biological aging, a compromised immune system.
One of the genes differentially expressed in dominant mice codes for “cocaine- and amphetamine-regulated transcript (CART) protein.” I don’t know what CART protein does, but just the name is evocative — descriptions of what happens to a mouse when he ascends to Alpha do, indeed, remind me of being 26 in a Cambridge dive bar with male friends who have snorted Ritalin. They don’t care if I’m ready to go home and go to bed; sleep is not on the menu. They are going to have another drink and then another and then another; they are going to grind on women on the dance floor and respond explosively when a stranger passes by too close, jostling their arm. The night will teeter on the sharp edge between fun and disaster.
I know a little bit about “social status mediated variation in hypothalamic transcriptional profiles of male mice”, because James Curley, a behavioral neuroscientist who studies social dominance and social behaviors, is my colleague in the Psychology department at the University of Texas. He recently went up for tenure, which requires giving a talk to the whole department on what you’ve done with the past decade of your life. Curley described a series of experiments where male mice are put together in a giant vivarium and allowed to establish their usual dominance hierarchy — and then, like a rapturing demiurge, he removes the Alpha and watches what happens next. Who ascends? (Usually, but not always, the Beta.) When? (Astonishingly quickly.) And (here is the behavioral neuroscience part) what happens to the ascendent Alpha’s body and brain? How do these changes affect Alpha Mouse’s subsequent behavior, such as whether his dominance collapses, or how despotic he is? It’s fascinating work.
The fact that I, a clinical and developmental psychologist who studies human children and adolescents, am in the same department as a behavioral neuroscientist who studies mice is not unusual. Psychology is a discipline that transcends species boundaries. In addition to studying mice, faculty in my department also study quail and voles and monkeys and rats. My first job in science was in a research lab that studied neurobiological mechanisms for opioid tolerance and withdrawal … in mice. I co-teach an undergraduate Introduction to Psychology course with a personality psychologist who wrote his dissertation on personality … in spotted hyenas. Our course, like most Intro Psych courses, has a lecture on classical and instrumental conditioning, which begins with salivating dogs and ends with exposure therapy for war veterans with PTSD, with stops along the way for cats in puzzle boxes and pigeons pecking for food and a baby taught to fear white fuzzy things. We always begin our course with a definition of psychology (“the science of mind and behavior”) and a description of our goal (“teaching you to think like a psychologist”) — but we’ve never articulated one core aspect of thinking like a psychologist, probably because we’ve been so close to it, we can’t see it, it is water to our fish: Human behavior is a type of animal behavior, because humans are animals.
Humans are animals. This was the thought that flashed through my mind last November when a young woman approached me after a talk I gave at the American Society of Human Genetics. Human. Genetics. You might think that a working scientist at a conference devoted to the study of human genetics would also have fully incorporated the idea that there are important continuities between the study of humans and of non-human animals, but you would be wrong!
My talk at the ASHG conference was part of a panel summarizing the work of a three-year, multidisciplinary Hastings Center working group on “Wrestling with social and behavioral genomics: Risks, potential benefits, and ethical responsibilities.” The panel went well, I think, except that one of my Internet trolls, a man I blocked on Twitter/X years ago but who continues to post vitriol undeterred, showed up in person to yell admonishments at us. I find it creepy when people obsessively hate things on the Internet; I find it creepier when the need to communicate those obsessive hates jumps from the screen to real life. But the interaction I’ve continued to think about in the weeks and months afterward is not with the sad older man who traveled gosh-knows how far and spent hundreds, maybe thousands, of dollars just to yell for a few minutes. It’s the one with the young woman, who was so confident when she asked: “Doesn’t it stand to reason that only social factors, not biological factors, explain social behavior?”
I didn’t give her a particularly articulate or compelling response, in part because I was so flabbergasted by her premise, and by how casually it was advanced. “Social laws are to be discovered only through the study of society; natural laws only through the study of nature.” So said the Russian Marxists, and so said this academic geneticist. For the record, I don’t think social behavior — in mice or people — is determined by biological factors or entirely explained by biological factors or reducible to biological factors. Even for mice, the way to know who is dominant and who is subdominant and who is subordinate is not to measure anything about their biology but to observe the operation of power: who aggresses against whom, who monopolizes resources? But only social factors explain social behavior?! The way I see it, the study of social behavior is part of the study of nature and the study of nature is part of the study of social behavior because humans live in societies and humans are part of nature. Because humans are animals.
Poets remember this. Here, for instance, are lines from Mary Oliver’s enormously popular poem, “Wild Geese”:
You only have to let the soft animal of your body love what it loves. ...
Whoever you are, no matter how lonely, the world offers itself to your imagination, calls to you like the wild geese, harsh and exciting - over and over announcing your place in the family of things.
And here are lines from Claudia Rankine:
To live through the days sometimes you moan like deer. Sometimes you sigh. The world says stop that. Another sigh. Another stop that. Moaning elicits laughter, sighing upsets. Perhaps each sigh is drawn into existence to pull in, pull under, who knows; truth be told, you could no more control those sighs than that which brings the sighs about. // The sigh is the pathway to breath; it allows breathing. That's just self-preservation. No one fabricates that. You sit down, you sigh. You stand up, you sigh. The sighing is a worrying exhale of an ache. You wouldn't call it an illness; still it is not the iteration of a free being. What else to liken yourself to but an animal, the ruminant kind?
What else to liken yourself to but an animal? I’ve been thinking recently about how many of my scientific interests, literary interests, and political commitments fall under that theme, which can be both horrible and liberating to contemplate. Near the end of Janet Malcolm’s Psychoanalysis: The Impossible Profession, she quotes one of the analysts she’s been interviewing:
To say “Man is not an animal” is to say nothing that banal people haven’t always said. To say that our essential humanity resides in precisely that part of our nature which is most instinctual, primitive, and infantile — animal — is to say something radical.
My plans for this Substack are still unclear, in part because I’m ambivalent about thinking out loud in public again (a topic for another post!). But this is what I want to think more deeply about — about the science and poems and memoirs and novels and political movements and personal experiences that remind me how my essential humanity resides in the soft animal of my body. I hope you will think along with me.
With excitement and trepidation,
Paige