This article appeared in One Story to Read Today, a newsletter where editors recommend one article to read. AtlanticMonday through Friday. Sign up here.
Of the dozens of hormones present in the human body, oxytocin may be the most overrated. ”, and even endlessly touted as a “source of love and prosperity.” It inspired popular books, TED talkScientists and writers claim that squirting it into a person’s nostrils can instill compassion and generosity. Online sellers sell snake oil oxytocin concoctions as “Liquid Trust.”
But with my colleague Ed Yong others offal Most of what is repeated talking about hormones teeth, exaggerated at bestSmell the chemicals won’t It definitely increases people’s cooperation and trust. Trials testing it as a treatment for children with autism spectrum disorders have yielded lackluster results. Although it has been shown to cause Race-cooperation meerkatprairie vole monogamy, parental care Marmoset and sheep-under other situationoxytocin can transform creatures ranging from rodents to humans Aggressive, That’s horribleflat prejudiced.
Now researchers are discovering that oxytocin is not only insufficient to build strong bonds, it may be unnecessary. new genetic research Prairie voles are fluffy, fist-sized rodents that are representative offspring of oxytocin’s form-fitting effects, suggesting that they can partner forever without oxytocin. doing. The discovery shook the foundations of an entire subfield of neuroscience, providing scientists with some of the oldest evidence that once seemed to show that oxytocin was the whole and final thing in animal affection. Hugs, after all, can probably happen without the classic hugging hormones.
Oxytocin isn’t necessarily obsolete. “This shouldn’t be taken as ‘Oh, oxytocin doesn’t do anything,'” says Cornell University neuroscientist Lindsay Thaler. Despite the messy, inconsistent, and even dubious data gleaned from human studies on hormones, the evidence from prairie voles has always been considered solid. kind is one of the few mammals They are monogamous and mate for life, co-parenting their offspring. For decades and across regions, researchers have documented how rodents snort at each other in their nests, comforting each other when stressed. actively rejection Other voles advance to attempt a homewreck. And every time they checked, “oxytocin sat in the middle of the story over and over again,” says behavioral neurobiologist Sue Carter. pioneered some of the first research into the bond between grasslands and volesThe molecular pathways driving behavior appeared equally clear: when triggered by social behaviors such as cuddling or having sex, a region of the brain called the hypothalamus pumped out oxytocin. The hormone then stuck to the receptor, causing a number of love-love effects.
Year of follow up the study I continued with that thought. When scientists gave prairie voles a drug, prevented oxytocin from binding to its receptor, the rodent began to gnaw its partner after trial and error. On the other hand, just stimulating the oxytocin receptor was enough to induce the voles to settle with strangers they had never mated with. The link between oxytocin and pair bonding was so strong, reproducible, and unquestionable that it became an established theory. Zoe Donaldson recalls receiving negative feedback about the grant. “
More than a decade ago, when Stanford University neurogeneticist and psychiatrist Nirao Shah and his colleagues attempted to cleave the oxytocin receptor from prairie voles using a genetic technique called CRISPR, they found themselves thought that the experiment would not work. Part of the goal, Shah told me, is a proof of principle. The researchers have yet to perfect their genetic tools in voles, as they do in more common laboratory animals such as mice. Producing a lineage of sorts, being unfaithful to their peers, and indifferent to their children, they have proven that the CRISPR mechanism has done its job.
That’s not what happened. The rodent continued to cuddle up to the family as if nothing had happened. The discovery was puzzling. At first, the team thought the experiment had simply failed. “I distinctly remember sitting there and just thinking, Wait a minute; how come there is no difference?Kristen Berenzen, a neurobiologist and psychiatrist at the University of California, San Francisco, who led the study, told me. It was as if I had successfully removed the gas tank from the car, filled it with fuel, and then witnessed the engine roar. Something may have gone wrong in the experiment. But that doesn’t seem to be the case, says Larry Young, a neuroscientist at Emory University who was not involved in the new study.
The explanation for how decades of oxytocin research may be upended is still being debated. Perhaps oxytocin can bind to multiple hormone receptors. suggested over the years, Carter told me. But some researchers, including Young, doubt more radical possibilities. Perhaps in the absence of normal receptors, oxytocin no longer does anything, forcing the brain to open up another avenue for affection. rice field.
The idea is not to dismiss old research entirely. Another prairie vole experiment using drugs to manipulate oxytocin receptors was done in adult animals grown with the hormone, said the UCSF psychiatrist and neuroscientist who led the new study. says Devanand Manoli. Rodent brains are hardwired to respond to oxytocin during development, so they couldn’t make up for the sudden loss of oxytocin later in life, but Stanford and his UCSF team found that We bred animals lacking the oxytocin receptor. from birth, may have prompted other molecules that can bind to different receptors to intervene. Perhaps the car didn’t need gas to run. The tank was removed from the beginning and instead everything is electric.
It’s easy to see this study as another blow to the oxytocin propaganda machine. But the researchers I’ve spoken to think the results are much more revealing than that. . For social mammals, partnering isn’t just sentimental. It’s an integral part of how we build communities, survive our childhoods, and enable future generations to do the same. , “These are some of the most important relationships for mammals. When oxytocin is around, it’s probably providing the vitality behind that intimacy. If not?” There is no single point of failure in evolution,” Manoli told me. Knocking oxytocin off its pedestal can feel like a disappointment.
