Between 1968 and 1972, a groundbreaking ethological experiment was conducted by the ethologist and behavioral researcher John B. Calhoun at the National Institute of Mental Health (NIMH). The experiment, known as “Universe 25,” was designed to investigate the effects of overpopulation and lack of social space on mice. The animals were given access to a large enclosure with 256 “apartments” arranged in 16 towers, with constant access to food, water, and nesting materials. The experiment began with eight healthy mice, four males and four females.
Initially, explosive growth was observed: the population doubled every 55 days and quickly reached 600 individuals. When population density became too high, social structures began to break down. Dominant males became extremely aggressive, while other males withdrew and became passive. Females grew neglectful and often killed or abandoned their young. Some mice isolated themselves completely, spending their time grooming, eating, and sleeping, never engaging in mating or social interaction with others.
In the nineteenth month, the population peaked at 2,200 mice, even though the enclosure was built to accommodate up to 4,000. Despite unlimited access to resources, mating ceased entirely and the colony died out. Although the mice lived in a physically “perfect” environment with unrestricted access to food, water, and shelter, a “behavioral sink” emerged—leading to social collapse and total extinction.
When Calhoun summarized his findings, he was struck by the emergence of a class of mice that appeared after the population explosion—mice that spent their time grooming and eating while avoiding all social contact. They were capable only of the simplest behaviors compatible with physiological survival. Calhoun believed that a human population bomb should be prevented to avoid human parallels, while critics argue that the threat of overpopulation is exaggerated.
Many cities on Earth today can be considered overcrowded, though hardly the Earth itself—this is a common counterargument, and it is difficult to refute. Yet regardless of whether one considers the planet overpopulated, some argue that Calhoun’s experiment serves as a warning of what modern society’s densely packed cities—with well-fed citizens enjoying every convenience—may be doing to our psyches.
Millions of people, especially young people, sit isolated in their rooms consuming junk—both through the food they eat and through their screens. Entrepreneurs in digital technology warn about what smartphone fixation is doing to our brains and our health. Tristan Harris, former design ethicist at Google, has explained that Facebook, Google, and others use advanced psychological insights to design their services to keep us engaged as long as possible. Today, programs at Stanford University and elsewhere train individuals in how to influence the way the public thinks.
The price we pay for constant screen fixation is not just our attention, Harris explains. We also become more stressed, more impulsive, and we stop thinking independently. Developers in Silicon Valley do not let their own children use smartphones because they know that scrolling and gaming continually trigger the brain’s reward system and foster addiction. Moreover, our capacity for empathy is affected when we stop interacting physically and reading others’ emotional cues.
Many young people today also grow up in an environment where quick thrills and kitsch are far more appealing than history, culture, and politics, which are often perceived as dull. Habitually, they park themselves in front of video games and movies with junk food and soda within reach. Daily, they are bombarded with rapid clips, trivia, stereotypes, hysterical sounds, and all manner of digital sludge constantly pouring from screens. Today, half of all men never read a book in their spare time.
For the human brain to function effectively, it creates behavioral patterns that determine what we will do at any given moment. Our ability to concentrate is extremely important—but also demanding. In an era when especially young people constantly occupy their brains with TikTok clips, mobile and computer games, gangster rap, and an orgy of other superficialities, both concentration and patience deteriorate.
Several researchers warn about how constant scrolling and staring at screens affect both sleep and mental health. They also raise alarms about how children’s fine motor skills are negatively impacted by increasing screen use. More and more children now struggle to do something as simple as tie a knot, sew, use scissors, do a somersault, or simply use a pen—because of constant screen tapping.
There is also a noticeable decline in reading, particularly among boys. Nine out of ten Swedish language teachers at lower and upper secondary school are deeply concerned about students’ declining reading comprehension. A book does not compete with scrolling or gaming, nor does it deliver the same quick dopamine hits. Mobile and computer use risk extinguishing the desire to read in an entire generation—potentially leading, in the long term, to an intellectual underclass of boys who in adulthood may be passed over by women.
The American social psychologist Jonathan Haidt has written extensively about the harmful effects of smartphone use, particularly on children. Haidt, professor of ethical leadership at New York University, calls “the destruction of attention span the greatest threat to humanity” and warns especially about the explosion of short, addictive video clips consumed daily by millions of young people.
In the mid-2000s, there was a sharp increase in the number of children who were unusually anxious and depressed compared to previous generations. In his 2024 book The Anxious Generation, Haidt sought to untangle the causes. He traces much of it to the rise of social media platforms like Instagram and the comparisons young people began making. It was also during this time that self-harm behaviors, especially among girls, became more prevalent.
The book focused on mental health, but Haidt argues that he greatly underestimated the damage caused by the destruction of attention span through screen use and social media: “Without the ability to pay attention for several minutes at a time—preferably 10 or 20—you will not be very useful as an employee, or as a spouse, and you will not be successful in life,” he explains.
This phenomenon goes far beyond mental health, Haidt says: it is changing human cognition and human attention—on a global scale. He also warns that AI risks worsening the problem. Certainly, AI can be of great benefit in many areas, but Silicon Valley has misled us many times before, as have Facebook and others, he says, claiming they concealed studies showing the downsides of social media. People need to feel meaning and usefulness, Haidt argues. Simply sitting in front of a screen will ultimately destroy that feeling. It becomes a soulless life.
Dr. Aditi Nerurkar, a physician, lecturer, and author affiliated with Harvard Medical School and specializing in stress and burnout, explains:
“In every healthy relationship, we have boundaries. We have boundaries with our children, our parents, our colleagues, our friends. And yet we have no boundaries—often porous ones—when it comes to our relationship with our phone… People bring their phones into the bathroom, sleep with them, eat with them, walk down the street with them… but in reality, it’s not passive, it’s active. And it has a profound effect on your biology, your brain, your psychology, and even social factors.”
The greatest threat right now is a process called neuroplasticity, according to Dr. Nerurkar, who describes it as a more sophisticated way of saying that your brain is like a muscle. By engaging in social media—with its high volume of low-quality, rapid videos—you are actively rewiring your brain for the worse. You increase stress, impair your mental health, attention, and cognition, and become more easily distracted, irritable, and less capable of complex problem-solving.
“This is just the tip of the iceberg,” Nerurkar says. “Short-form video content and its ripple effects cross many boundaries. It not only rewires your brain, it rewires your body. It affects your sleep, increasing the risk of heart disease later in life. And consuming graphic videos and images can increase the risk of PTSD through trauma—even if you were not there.”
The digital lifestyle, combined with overprotective parenting, has additional and extremely serious consequences. In the book The Coddling of the American Mind, Haidt describes the epidemic of fragility, dependency, and resistance to free speech spreading among university students in the West. This, he argues, stems from parents who—having more time and resources than any previous generation—never dared let their children out of sight, constantly monitoring, serving, and coddling them.
According to Haidt, this helps explain phenomena at American universities that seem utterly bizarre to the average person: demands for “safe spaces” where students are shielded from uncomfortable opinions and ideas; “trigger warnings” on course literature that may contain ideas students find disturbing; and people claiming they feel unsafe simply because others hold different views.
Haidt notes that these overprotected individuals, in the United States as well as in Sweden, more easily and more frequently suffer from mental illness than their predecessors. If one has not learned to tolerate adversity, one becomes more vulnerable when it arises. As for antidepressant prescriptions, Sweden ranks among the highest in Europe.
Psychologist Jean Twenge, who specializes in generational differences, identifies a clear dividing line at the birth year 1995. Those born in or after that year were the first to grow up with smartphones in their pockets and social media everywhere. When digital socializing replaces real-life interaction, today’s youth tend to mature more slowly than previous generations: 18-year-olds behave like 15-year-olds once did, and 13-year-olds like 10-year-olds.
Heightened sensitivity and a culture of victimhood have also provided fertile ground for hysterical activism and obsession with perceived injustices—whether related to climate, migration, or minority issues. The world is divided into “good” and “evil,” where those who disagree on a “sensitive” issue are labeled evil, and terms like racist are casually thrown around. Misinterpretations risk becoming the rule rather than the exception in a world where the principle of charity has become unknown, and where we cannot even be bothered to check facts before speaking.
In the worst case, what ultimately awaits is a society in which people have stopped thinking in any meaningful sense. Where the most common form of “thinking” is wishful thinking—if thinking occurs at all. And where what we call thinking becomes merely the repetition of learned clichés, fake news, and constant projection onto others.
Michael Delavante, The last thinking generation
Sources:
1. Universe 25 Experiment: https://www.the-scientist.com/universe-25-experiment-69941 Also see: https://x.com/mindsetmachine/status/2023510579873493392?s=20
2. Kriget om din uppmärksamhet , Sverigesradio.se 06 feb, http://sverigesradio.se/sida/avsnitt/1016668?programid=1272
- How a handful of tech companies control billions of minds every day | Tristan Harris
https://www.youtube.com/watch?v=C74amJRp730&t=794s - Varannan man läser inte böcker på fritiden: https://www.scb.se/pressmeddelande/varannan-man-laser-inte-bocker-pa-fritiden/
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- DN Debatt. ”Dagens barn kan inte ens slå en kullerbytta”Dagens Nyheter, 2024-01-
- Diary Of A CEO Podcast: Jonathan Haidt & Dr Aditi Nerurkar on Global ‘Brain Rot’ Crisis (Transcript)February 16, 2026 Also see: https://www.youtube.com/watch?v=EScgrk7oEwU&t=7835s
- Diary Of A CEO Podcast: Jonathan Haidt & Dr Aditi Nerurkar on Global ‘Brain Rot’ Crisis (Transcript) February 16, 2026 Also see: https://www.youtube.com/watch?v=EScgrk7oEwU&t=7835s
- Diary Of A CEO Podcast: Jonathan Haidt & Dr Aditi Nerurkar on Global ‘Brain Rot’ Crisis (Transcript)February 16, 2026 Also see: https://www.youtube.com/watch?v=EScgrk7oEwU&t=7835s
- Diary Of A CEO Podcast: Jonathan Haidt & Dr Aditi Nerurkar on Global ‘Brain Rot’ Crisis (Transcript) February 16, 2026 Also see: https://www.youtube.com/watch?v=EScgrk7oEwU&t=7835s
- Vem fick genration Z att hata yttrandefriheten? https://timbro.se/smedjan/vem-fick-generation-z-att-hata-yttrandefriheten/
- Vem fick genration Z att hata yttrandefriheten? https://timbro.se/smedjan/vem-fick-generation-z-att-hata-yttrandefriheten/
