The chemistry of attention, the manipulation of perception, and the fracturing of a society that no longer shares the same reality.
You think you're using the phone. In reality, the phone is using you.
Every night, millions of people open an app without looking for anything specific. They just want to distract themselves, silence the noise inside for a while, fill a void they can't name. And every night they leave the screen with their brains a little more changed than when they went in, without even noticing.
That is the silent revolution of our time. For the first time in history, it is possible to modify the brain chemistry of millions of people simultaneously, continuously, in a personalized and invisible way. No one needs to convince you of anything. It is enough to change the state from which you draw your own conclusions.
When your biology changes, your perception changes. When your perception changes, your reality changes.
What's happening in your brain tonight
Let's say tonight is you. You arrive home tired, feeling unwell, with a bit of anger directed at no one. It's after 2 a.m. and you know you should be sleeping. You open the app anyway. You don't like anything. You just stay a second longer on a video that touches on something personal.
Take a moment to look at your body, because that's where the clue lies. Your jaw is slightly clenched. The heat rising to your chest. Your shoulders drawn up towards your ears. That state of alertness is precisely the gateway through which everything else enters.
The algorithm doesn't need your like. That second is enough. It registers it as a sign of interest and starts serving you more of the same.
Meanwhile, something very specific is happening inside your head. Every time something triggers an intense reaction—fear, outrage, desire, validation—your brain releases dopamine. Dopamine is often called the pleasure molecule. Its real function is learning: it marks what is worth remembering and what is worth revisiting (Schultz, 1998).
So the system learns what hooks you. And you learn to come back.
If you arrive feeling unwell, the effect is even more subtle. A restless brain seeks relief before truth. And the greatest biological relief comes when it finds an explanation: a cause, a pattern, a culprit. Uncertainty decreases, stress activation eases, and reward circuits activate. You feel you finally understand something. It doesn't matter if it's true.
That's how he convinces you
Repeat this a few nights and change your perspective.
The brain functions as a predictive organ, far from being a camera that neutrally records the world. It anticipates reality based on models built from prior experience, and only corrects them when the error becomes impossible to ignore (Friston, 2010; Barrett, 2017). You see the world your brain expects to find.
Each video you consume slightly adjusts that model. Each repeated narrative reinforces certain circuits. Each exposure makes an idea more familiar and, therefore, more believable. There comes a point when you stop evaluating the information and simply recognize it. And the brain confuses the familiar with the true.
It is one of the best-documented biases in psychology (Kahneman, 2011). A false statement, repeated often enough, requires less effort to process. And what requires less effort feels truer.
This is how he convinces you: through repetition and chemistry, long before arguments.
This is how it radicalizes you.
Radicalization almost never happens suddenly. It comes through habituation.
First, the emotional landscape changes. Then, what you perceive. Finally, who you believe you are. Ideology arrives last, when the ground is already prepared.
Let's put a name and a face to it. Carlos is twenty-three years old, his body weary, and he carries a deep-seated irritation he doesn't know how to express. Something has been squeezing his chest for months, and it has no name. He's not starting from scratch. In Spain, almost half of young people already see feminism as a tool for political manipulation, and among young men, feminist identification has plummeted to 261% (Youth and Gender Barometer 2025, Reina Sofía Center). The groundwork has been laid before Carlos even touches the screen. The algorithm only needs to find him there, stirred, searching for where to unload.
And a nervous system on high alert doesn't seek the truth. It seeks to lower its activation. Tonight, Carlos lingers a second longer on a video of someone stating with composure what he doesn't dare to articulate: that the problem is them, that they've taken something from him. Something measurable happens in his body. The tension finds an outlet, the anger finds direction, and the brain rewards this relief with a small chemical release. For a moment, he stops feeling lost. He begins to feel justified. His body has just learned that there is calm within, and it will want to return.
The fact that feminism is strong and active in the streets of Spain doesn't stop this. It fuels it. It gives Carlos's resentment a visible adversary to target, a clear figure to blame. The clearer the enemy, the purer the relief.
From that point on, his feed ceases to be random. Each video that keeps him watching for one more second teaches the system what soothes him, and it serves him more of the same, each time more intense. This is measured: when Media Matters (2021) opened a new account and interacted only with one type of hateful content, the algorithm filled the screen with far-right material in just a few hundred videos. An audit of TikTok's own system described these recommendation tunnels (Shin and Jitkajornwanich, 2024). Carlos doesn't choose this narrowing. He inhabits it.
Months later, his world has shrunk. He speaks in phrases that aren't his own. People he once cared about make him uncomfortable. He's still just as alone, with the same weight on his chest as the first day, but now he has a story that explains why, and that story has cost him relationships. The unease hasn't gone anywhere. It's just changed hands.
And here's what his body can't see. That precariousness that's squeezing him, the work that never comes, the impossible rent, is real, and its origin is economic. But while Carlos vents his rage against women, no one vents it against the one who's exploiting him. He's ended up paying for courses and subscriptions from the very men who profit from his anger, believing he's paying the one who's saving him. The algorithm didn't plant the ideas in his head. It found a nervous system seeking relief and sold it a scapegoat.
It's important to say this carefully, without mincing words. No feed pulls a trigger, and gender-based violence has roots far older than any app. But the climate matters. In a country where gender-based violence persists, Feminicidio.net recorded around ninety-six murders of women for gender-related reasons in 2025 alone, and January 2026 was one of the worst starts to the year. In that context, a machine that sows contempt for women in thousands of Carlos on an industrial scale is not a technical detail. It's a public health problem.
This polarizes us all.
Multiply this by millions of people like you, each with their brain trained by a different algorithm, and the political problem of our time emerges.
The system rewards what it retains, regardless of its truth. And few things are as easily retained as hostility toward the opposing group. An analysis of nearly three million messages found that those attacking the rival side are shared about twice as often as those praising one's own, and that each word directed against the other side increases the likelihood of the message spreading by nearly seventy percent (Rathje et al., 2021). Hate travels faster than agreement, and the algorithm takes advantage of this.
You and someone who lives on the same street may seemingly read the same news and inhabit incompatible psychological universes. You share the physical space. You no longer share reality.
Shoshana Zuboff (2019) aptly named it: the business is about predicting and modifying your behavior, beyond simply selling your data. The underlying product is the ability to influence future human decisions.
A democracy survives when we disagree on interpretations. It breaks down when agreement on the facts before us all disappears.
The real danger: they reformat your mind.
And here's what should really alarm you.
After a few months, the change reaches something deeper than your ideas: your very way of perceiving. Your reward system, your attention, and your way of reading the world have been reorganized around what kept you glued to the screen the longest. The change happens in the brain that produces your ideas, before the ideas themselves. And a reformatted brain no longer needs anyone to convince it. It convinces itself.
That's the kidnapping. You retain your freedom to have an opinion. What gets reorganized is the brain from which you form those opinions.
The exit begins in the body
Getting out of this requires more than turning off your phone. And it requires less brainpower than you think.
Go back to tonight's body: the clenched jaw, the heat in your chest, the 2 a.m. rage. That state of alertness is the keyhole, and that's where the algorithm enters. A regulated nervous system is much harder to hijack. When your body isn't constantly on high alert, the content that feeds on alarm loses almost all its grip.
That's why true sovereignty begins before any critical thinking. It begins in physiology.
The next time you notice a video triggering your anger, don't argue with it. Put your phone down for thirty seconds. Lengthen your exhalation longer than your inhalation, two or three times, until your shoulders relax. You're freeing your body from the state the algorithm has trapped you in. From that calm, and almost only from there, do the questions become relevant again: who's profiting from my outrage, where is this coming from, what am I missing?.
Freedom in this century begins in the body. A nervous system is trained not to take the bait at every opportunity, and from that calm, the mind recovers. As long as your body remains in a state of alert, someone else is reprogramming it for you.
Sources and references
Barrett, LF (2017). How Emotions Are Made. Houghton Mifflin Harcourt. Professor of Psychology and Neuroscience of Emotion.
Friston, K. (2010). The free-energy principle: a unified brain theory? Nature Reviews Neuroscience, 11(2). Computational neuroscientist.
Kahneman, D. (2011). Thinking, Fast and Slow. Farrar, Straus and Giroux. Psychologist, Nobel Prize in Economics 2002.
Media Matters for America (2021). Report on TikTok's algorithm and recommendation tunnels to far-right content. Media research organization.
Rathje, S., Van Bavel, J.J., & van der Linden, S. (2021). Out-group animosity drives engagement on social media. Proceedings of the National Academy of Sciences (PNAS), 118(26). Social psychologists from Cambridge and New York.
Schultz, W. (1998). Predictive reward signal of dopamine neurons. Journal of Neurophysiology, 80(1). Neuroscientist; described dopamine as a reward prediction error signal.
Shin, D., & Jitkajornwanich, K. (2024). How Algorithms Promote Self-Radicalization: Audit of TikTok's Algorithm Using a Reverse Engineering Method. Social Science Computer Review, 42(4). Audit of the algorithm and the radicalization itineraries.
Zuboff, S. (2019). The Age of Surveillance Capitalism (The Surveillance Capitalism). PublicAffairs / Paidós. Professor Emerita at Harvard Business School.