Last week, October 10th, marked the 32nd World Mental Health Day. This day, initiated by the World Health Organization (WHO) in 1992, aims to raise awareness about mental illnesses and psychological health. According to data published by WHO over a decade ago, around 450 million people worldwide suffer from mental developmental disorders. This proportion is higher than many people might imagine.
But today, our focus is not on popularizing knowledge; rather, I want to discuss an incident related to the topic of mental health that happened earlier this year—one that I personally find worth talking about.
This incident itself is not new, but the problem is that despite numerous media reports, each focused only on certain aspects of the event, there was never a comprehensive account. This led to widespread misunderstandings among many people about the whole story.
The incident in question occurred this summer when a pregnant woman from Sichuan posted her prenatal test results online. The report indicated that a higher number of Y chromosomes were detected in the sample, suggesting an XY and XYY mosaicism or other complex karyotype.
To most people, terms like mosaicism or complex karyotype might sound unfamiliar. But the term XYY stood out—yes, it’s related to what’s known as Supermale Syndrome. XY is male, and XYY, with an extra Y, implies being “more male than male.” Some even call it a “demon gene” and claim it denotes a born criminal. At that time, this pregnant woman sought advice from netizens on whether to keep the baby. Soon, various online responses emerged—ranging from casual advice to baseless claims by influencers, and even professional doctors’ explanations clarifying that supermale isn’t a born villain.
After a flurry of mixed messages, the pregnant woman later shared the final outcome online: she decided to terminate the pregnancy and not bring the child into the world.
Netizens, upon seeing this, remarked, “After all that discussion, she still didn’t keep the child, right? Doesn’t this prove that supermale means a so-called born bad seed?”
By this point, the buzz around the topic died down, and people moved on. But the conclusion left a massive misunderstanding.
Today, let’s delve into this incident. First, where did the claim that supermale means a born criminal originate?
The term “supermale” first gained popularity not from any scientific dissemination, but from a South Korean reality show called The Most Recent Parenting, also known as My Golden Child. The show, with a Douban rating of 9.1, focuses on observing families as they raise their children.
In the show, there was a child named Jae-woo, a troublemaker from a parent’s perspective—constantly using foul language, uncommunicative, and prone to emotional outbursts. As he grew, his violent behavior became more extreme, even injuring his mother. Eventually, he began to self-harm.
Concerned, the production team took him for a medical check-up. The results revealed that Jae-woo had the XYY, or supermale, gene. This was the first time many viewers encountered the term supermale. Upon hearing “supermale,” many assumed that having an extra Y chromosome—associated with male traits—would mean a heightened tendency for violence.
Thus, people began referring to children with violent tendencies as supermale children. From then on, supermale became linked with violence.
However, if you watched The Most Recent Parenting, you’d notice a peculiar trend—whether coincidentally or for dramatic effect, many of the children featured had behavioral issues. Some were overly emotional, while others were hypersensitive. And most of these problems, including Jae-woo’s, stemmed from poor parenting.
But because the term “supermale” was so catchy, people ignored the subsequent expert explanations and only remembered the association between supermale and violence.
Moreover, over the past decades, the spread of the supermale narrative has followed a similar pattern. A misunderstanding arises, quickly spreads, and by the time authoritative information is available, the public has already moved on, remembering only the misconception.
For example, in 1966, The Lancet published a study involving genetic tests on 315 men, discovering 9 with XYY, all of whom were mentally disturbed criminals. The researchers concluded that men with the XYY chromosome were more likely to become criminals. This study was soon refuted by the scientific community, but the clarification went unheard by most, who only remembered the initial conclusion.
Similarly, in 1967, a notorious serial killer named Richard Speck was captured after brutally murdering 8 women within an hour. Speck’s lawyer claimed he had the XYY chromosome. However, subsequent tests showed Speck had a normal XY chromosome. The lawyer’s statement was merely an attempt at a reduced sentence. Despite being debunked twice, the public retained the narrative that Speck was a supermale, ignoring the professional findings.
In reality, there have been many studies on supermale throughout history. But often, rumors spread widely, while the truth remains untold.
For example, in 1968, The Journal of Medical Genetics published a study showing that the proportion of supermales among Scottish prisoners was roughly the same as in the general population.
In 1976, Science magazine published a study on men over 184 cm (6’0″) tall from 1944 to 1947, given that supermales are typically taller. Without diving into details, the researchers found that the proportion of supermales among serious offenders didn’t increase. However, in lesser offenses, crime rates correlated with lower intelligence.
In simple terms, among minor offenders, those with lower intelligence were more common. This is often because such individuals struggle to understand rules or perceive others’ intentions, leading to conflicts.
It’s important to highlight that supermales tend to have a slight disadvantage in intellectual development.
Research has shown that in comparable environments, a supermale individual raised alongside their siblings will have lower intelligence than their siblings in 82% of cases. In 9% of cases, there is no difference, and in another 9%, the supermale individual outperforms their siblings.
And even though supermales might have slightly lower average intelligence, it’s not significant. Typically, their intelligence is about 10 to 15 points below the average of their peers, far from being medically classified as intellectually disabled.
Now that we’ve addressed the misunderstanding around supermale and whether it implies being born “bad,” let’s clarify a few things. First, supermale is not a “crime gene.” The higher proportion of supermales among minor offenders isn’t due to inherent violence but rather the slight intellectual deficits associated with Supermale Syndrome.
Second, Supermale Syndrome doesn’t necessarily imply intellectual deficits—it just carries a probability. The pregnant woman’s decision to terminate her pregnancy might have been based on this consideration.
Finally, regarding the appearance of supermales: they do tend to be taller. But aside from height, individuals with Supermale Syndrome don’t have unique facial features. The online claims about supermale appearance are based on observations of certain common traits among the group. But in reality, those traits can exist in other people as well. Some conditions are diagnosable through physical appearance, like Down syndrome, Turner syndrome, or Williams syndrome, but Supermale Syndrome is not one of them.
In other words, supermale is not a mental disorder, nor does it imply a predisposition to violence; it is simply a genetic phenomenon. In fact, 80% to 90% of individuals with Supermale Syndrome would never know they have the XYY chromosome unless tested.
But the issue is that each time there’s a supermale-related media event, it follows the same pattern of spreading. As Mark Twain once said, “A lie can travel halfway around the world while the truth is still putting on its shoes.”
This tendency isn’t limited to rumors; many things spread this way. As Xiamen University’s communication professor Zou Zhendong put it, “The world of public opinion is like the wind—lighter things spread easily, while heavier ones struggle to get through.”
You see, the notion that supermale equals a bad person is lightweight and simple, making it easy to spread. On the other hand, the serious scientific explanations that follow are more complex and less likely to go viral.
Now that we’ve covered the misconceptions about Supermale Syndrome, what is the reality of being supermale?
First, supermale isn’t a hereditary disease; it’s a rare anomaly. Normally, a male’s chromosomes are XY, while a female’s are XX. In rare cases, an error during the second meiotic division of germ cells results in a sperm cell with an extra Y chromosome. If this cell combines with an egg, it results in an XYY chromosome. You don’t need to delve into the specifics; just know that the appearance of XYY is a rare incident during germ cell combination.
Second, just as an extra Y chromosome can appear, so can an extra X chromosome—resulting in XXX, also known as Triple X Syndrome. Similarly, many individuals with Triple X Syndrome do not exhibit significant abnormalities, and so on.
Beyond the scientific explanations, today we also discussed another issue: how to observe trending events. Many of these events are essentially like a feather tied to a dumbbell. The feather is light and spreads easily, but the dumbbell is heavy and doesn’t easily take off. However, seeing the dumbbell beneath the feather might be the key to understanding the truth.
