My family is full of risk-takers. Or so goes the family lore. My father, who started riding motorcycles when he was 12, almost died zooming around a racetrack in his 40s. For many years, he was an aircraft carrier pilot for the Navy, which means he was landing giant planes onto tiny runways in the middle of the ocean. If you missed the “tailhook” on the deck when landing, you often plunged to the bottom of the sea and that was it. Many of his carrier-pilot buddies died during routine exercises. Old age didn’t tame him. On his 80th birthday, he jumped out of an airplane over California.
My mother’s mother Clarissa, a vaudeville dancer, was also a high diver in Japan, something she volunteered for even though she didn’t know how to swim. She would dive into a swimming pool from 15 to 20 feet up, and once she had plunged into the deep end, trained dolphins would swim over to deliver American and Japanese flags to her, which she then sewed together—underwater. Another close family member spent a year hanging around with Marxist urban guerillas in Colombia in the 1980s, at the height of paramilitary violence in the country. The thrill-seeking and risk-taking of other relations is less storied, but you can find it if you know where to look—or maybe, if you want to frame it that way.
My mother always explained my father’s propensity for doing dangerous things in terms of how much testosterone he had charging through his veins. She was an educated person, and fiercely feminist, but she couldn’t resist falling back on this cultural shorthand for masculinity—for physical daring, aggression, and love of risk. Of course, she never described her own mother’s taste for physical stunts and adventure in these terms. Her take on my father was shaped by what has turned out to be a stubborn myth: Men are more aggressive and take more risks because they’re born that way. Their biology makes it inevitable. And it’s all because of a single hormone with a capital T.
Read more: “The Hidden Sexism of How We Think About Risk”
Scientists began poking holes in the idea that testosterone promotes aggression over a decade ago. A study published in Nature in 2009 found it isn’t testosterone itself that induces aggressiveness, but folklore about how the hormone works. The scientists who did the research found that people who acted more aggressively were the ones who believed they received testosterone, even if they got a placebo.
But these findings didn’t do much to deflate popular stereotypes. Eight years later, in 2017, Cordelia Fine published a book, Testosterone Rex, to try to dismantle the myth. Fine took aim at testosterone as an explanation for not just male aggression but risk-taking, promiscuity, competitiveness, and dominance. And in 2019, Rebecca Jordan-Young and Katrina Karkazis published Testosterone: An Unauthorized Biography. Both books argued that the classic studies that supposedly proved a link between testosterone and aggressive behavior were deeply flawed. The idea of testosterone as the “essence of masculinity” shaped what scientists asked about it from the start, they wrote, as well as how evidence was collected, and how findings were communicated.
It’s now 2026, and yet the need for myth-busting persists. On New Year’s Day this year, The New York Times published an essay by primatologist Robert Sapolsky entitled “Testosterone Is Misunderstood.” Sapolsky writes that scientists believe what testosterone actually does is make people more sensitive to threats to their status—more responsive to perceived sleights—rather than directly causing aggression. Causality may even move in the opposite direction: Evidence suggests aggression may trigger a surge in testosterone. So the aggression we see in modern society isn’t the fault of the hormone, but can be blamed on the status aggression affords to men, he argues. “This raises an intriguing possibility: What would testosterone do in a situation where status comes from being kind?”
Earlier this month, scientists published the largest and most systematic takedown of the testosterone mythos yet: a review of 52 studies, covering 17,000 participants, focused specifically on risk-taking. The authors of that study, published in Neuroscience and Biobehavioral Reviews, found that there was zero relationship between testosterone and appetite for risk. The lack of relationship also didn’t depend on sex: It was no different in men than in women.
Although the net result was zero, the data reported by individual studies was all over the map. The researchers explain that this is because of differences in how risk-taking and testosterone were measured. Studies that relied on lottery tasks to measure risk-taking showed a small positive association, while studies measuring risk-taking via other impulsive games or self-report surveys did not. Similarly, the researchers found that studies relying on physiological measurements such as finger length sometimes suggested a link, but more rigorous ones using direct hormone measurements through blood or saliva, or experimental doses of testosterone, did not.
Read more: “Dude, Where’s My Frontal Cortex?”
The idea that testosterone is the fuel for certain behaviors we associate with masculinity got a curious start in Paris in the Victorian age. In 1889, physiologist Charles Brown-Séquard, aged 72, found that injecting testicular extracts—from crushed testicles of dogs and guinea pigs—had suddenly returned to him the strength and intellectual powers of his younger self. He presented his findings at the Société de Biologie that year. Soon after, chemists began cooking up his “elixir of life,” and thousands of physicians began prescribing it across Europe and the United States. Only later was it discovered that the extract contained such tiny concentrations of testosterone that they couldn’t have had any biological impact. The first steroid craze was driven by the placebo effect.
More than half a century later, during the 1954 Summer Olympics, Russian weightlifters used synthetic testosterone to enhance their ability to compete, and from there it spread through elite athletics and bodybuilding. But the first study to link testosterone to aggression in humans was conducted in prisoners in 1972. These studies were widely covered in the media, and the legend took off.
Social media influencers, fueled in part by the testosterone supplement industry, are doing their part to keep the fiction alive today. A study from February of this year reviewed several dozen Instagram and TikTok accounts that promote the idea of a “masculinity crisis,” encouraging healthy young men to get unnecessary testosterone testing and treatment, despite serious health risks associated with an excess of the hormone, including heart problems, infertility, reduced libido, and erectile dysfunction. The social media posts had a combined audience of 6.8 million followers and more than 650,000 “likes,” according to the research. Many of the posts were linked to purchases of specific products. The testosterone supplement industry itself also directly pushes an association between the hormone and certain forms of aggressive masculinity through its own advertisements. Some ads for T8, for example, feature images of a group of men bathed in dirt, mouths wide in a kind of primal roar.
The testosterone myth is sticky at least in part because it's useful: As Jordan-Young put it, it supports existing gender hierarchies by implying that if men dominate in certain areas defined by aggression, competition and risk-taking, it’s inherent and inevitable, not the production of centuries of social norms.
Either way, I’m left with a question: What were my family members chasing? I suspect it has something to do with storytelling—those who tell the stories, and those want to be worthy of them. 
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Lead image: JEGAS RA / Adobe Stock
