How companies create products that hook you and shape your habits

Distilling books - Number 16

Welcome to Mental Garden. The following letter is part of our “Distilling Books” collection, in which we extract the most revealing ideas from literature. For the complete library, click here.

🏷️ Categories: Software, Behavior, Habits.

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“79% of people check their phone within the first 15 minutes after waking up every morning.”

“Humans are motivated to seek pleasure and avoid pain, to seek hope and avoid fear, and finally, to seek social acceptance and avoid rejection.”

“If it can’t be used for evil, it’s not a superpower.”

— Nir Eyal, Hooked, How to Build Habit-Forming Products

It’s happened to you, I know.

You grab your phone to check just one notification. That’s it.
An hour later, you’re still there: scrolling, watching videos, liking posts—without even knowing exactly how you got there. The truth is, you only came for one notification…

Coincidence? I don’t think so.

Today you’ll understand why this happens—because yes, there’s a reason behind it.

We’ll talk about the habit-creation cycle companies like Facebook, Instagram, or X use to keep you hooked on their products and generate revenue—leveraging human psychology to capture and hold your attention as much as possible.

Here are the secrets behind the apps you use every day.

Be a user or be used

Technology has changed our habits to the point where actions like checking notifications are now unconscious. We spend hours on social media, sometimes without even noticing. And it’s not a lack of self-control; it’s designed that way.

Nothing in app design is a coincidence.

Many people have gone from being users to being used by technology. Knowing how to identify when you’re acting consciously and when you’re being nudged by design is the first step toward regaining control.

What is a habit?

To understand how technology reached this point, we need to understand what a habit is.

A habit is an “automatic behavior triggered by contextual cues.”

It’s something you do without much thought, like checking your phone when you wake up, or opening Instagram out of boredom. It’s a repetitive behavior engraved in your brain until it activates without a truly conscious decision. Like when your alarm goes off and you get up without thinking, just out of pure routine.

And that’s the power of habits: they’re automatic.

When something becomes a habit, we stop questioning it. That’s exactly the goal of the products and apps we use: to make their use automatic. And for the company, this creates a barrier to entry for competitors. Look at these examples:

• Google is the automatic answer when you have a question.

• WhatsApp is the automatic answer when you need to communicate.

• Uber is the automatic answer when you need to get around.

There may be thousands of better alternatives, yes—but none more habitual.

People use these technologies out of sheer routine. The habit is so ingrained that convincing them to switch becomes nearly impossible, even if there are better options.

For a company, if its product becomes a habit, it’s already won.

If you feel lonely, you go to Facebook. Bored? To Twitter or TikTok. Have a question? To Google. Companies position themselves in your mind as your first response. This automatic first response happens thanks to the availability heuristic.

In other words, your brain creates shortcuts to make decision-making easier.

Everyone wants to be that automatic response in your brain, and they try to achieve it through a 4-phase cycle designed to keep you hooked. Let’s break it down…

The Hook Model

This habit-creation process is based on a 4-phase cycle:

1. Trigger

2. Action

3. Variable Reward

4. Investment

Each spin of the cycle strengthens the habit. Each repetition hooks you more. It’s like rolling a wheel downhill—once it starts turning, it becomes harder and harder to stop…

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1. Trigger

Triggers are the spark that initiates behavior. There are two types:

• External (reviews, recommendations, ads)

• Internal (boredom, anxiety, loneliness, FOMO, or other feelings)

Apps first attract you with external triggers, which are what get you to try the product in the first place. Over time, they try to keep you hooked using internal triggers.

Take Instagram, for example:

You open Instagram when you see a notification on your phone. The trigger motivates you to log in and feel validated by the new “like” you got—or maybe to feel less bored when you see a funny video a friend sent you.

Whether it’s a “like” or a message from a friend, Instagram taps directly into your emotions.

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2. Action

This is key—pay attention to how we define action.

An action is the simplest behavior you can do in anticipation of a reward. For example: clicking, scrolling, or tapping an app button. Psychologist BJ Fogg’s model explains it perfectly:

Action = Motivation + Ability + Trigger

• Motivation (pleasure, fear, social validation, FOMO, etc.)

• Ability (the easier the action, the more likely it is to happen)

• Trigger (notification, sound, vibration, etc.)

If one of these three elements is missing, the action won’t happen.

Apps like X, Instagram, or TikTok know this well. Scrolling is the current standard because it’s so easy—even a small child can do it. And when searching for information, the algorithm chooses the content for you so you don’t even have to think.

The easier the action, the more likely it is to happen.

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3. Variable rewards

Here’s where the magic lies: uncertainty. Remember this—variable rewards.

If you always received the same reward, you’d lose interest quickly. Dopamine doesn’t spike from the reward itself, but from the uncertainty—the anticipation of something potentially pleasurable but unknown.

There are different types of variable rewards:

• Tribe: Social validation (likes, comments, new followers).

• Hunter: Discovering something new or finding limited-time deals. Shein, Amazon, and every shopping app are experts at this.

• Self: A sense of mastery or achievement (levels or status in an app). This is why so many people use Duolingo—it makes you feel capable through levels.

The key is that rewards connect back to the initial motivation, creating an endless loop of anticipation and reward. That’s the dopamine cycle: you act because you anticipate pleasure. The uncertainty of discovery releases dopamine in your brain and keeps you craving the next reward.

That’s how infinite scroll works—it’s like a slot machine.

You never know what you’ll see, but you know that if you keep scrolling, eventually you’ll see something pleasurable. So you keep scrolling more and more, spending more and more time. This behavior was already proven in 1948 with pigeons and rats.

We’re not so different from other animals.

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4. Investment

This is where the IKEA effect comes in.

The more time, effort, and information you invest in a product, the greater your commitment to it. That’s the IKEA effect: you value something more simply because you put effort into it.

You make dozens of these “investments” daily without realizing it…

Customizing your profile, uploading a photo, saving content, or following accounts are all small investments. They make you feel more connected to the product and set the stage for the next trigger to have even greater impact.

How does the next trigger gain more impact? Easy.

Your investments generate data and content that feed the product’s algorithm, making it more personalized, more efficient, and more addictive.

• The more you use TikTok, the better the algorithm learns your tastes—and the more irresistible it becomes.

• The more you use Instagram, the more contacts and followers you accumulate, and leaving the app feels like throwing away years of your life. Your files and followers hold you hostage.

• The more you use Pinterest, the more images you save, and the smarter the algorithm gets about you.

And so it goes with every single app you use today.

Even Substack Notes is just copying a model they already know is addictive.

This cycle explains how digital companies create irresistible products.

But here’s the interesting part: If you understand this mechanism, you can use it to your advantage.

• Why not create conscious habits that actually benefit your life?

• Why not apply the same model to build healthy habits like reading, meditating, exercising, or studying?

It’s not just about being aware of what others are doing to you.

It’s about deciding, intentionally, what you want to do.

✍️ Your turn: How could you design your own hook cycles to build habits that truly benefit you? Build habits intentionally.

💭 Quote of the day: “To start an action, doing must be easier than thinking.” — Nir Eyal, Hooked

See you next time! 👋

References 📚

1. Eyal, N. (2014). Hooked, How to Build Habit-Forming Products