Reading versus Scrolling

Avinash Kumar
Feb 1
7 min read

One may wonder, how a barely less than decade old phenomenon of short reels and videos has converted itself into a mass addiction. The people looking at their mobile phone screens, either when static or even when moving , is an extremely common site. The average time spent on social media and reel consumption by billions of people across world is to the tune of 02 to 04 hours per day.

On the other hand, 'reading' among the masses started in the 19th century i.e. more than 200 years ago. But reading has never been converted into an addiction for the people at large.

How such a recent development of reels and short videos, has become so deeply entrenched in the habits of the billions, while the habit of reading is nowhere near to the former. Could it be because of lower brain energy consumed in watching short videos as compared to reading a good non fiction book?

The help of AI to answer above question led to the following information:

Short answer — not exactly. I couldn’t find a published, direct head-to-head study that measures whole-brain energy (glucose/oxygen use) comparing reading a good-quality non-fiction book versus watching short, random social-media videos/reels. The literature does, however, let us say useful things about how (1) brain energy is measured, (2) how much task-related energy typically changes, and (3) how reading vs. short videos differ in which brain systems they recruit. (ScienceDirect)

What the evidence says (short, cited points)

Task-related energy changes are small. Recent reviews of the “metabolic cost of cognition” find that goal-directed cognitive activity increases brain energy use only modestly — often on the order of a few percent above the brain’s baseline metabolic rate. That means the extra calories burned by doing a demanding mental task are small. (ScienceDirect)
The brain’s baseline is large and tightly regulated. The human brain already consumes ~20% of the body’s resting energy and most of that supports ongoing signaling and maintenance; only a minority of energy is added when switching tasks or increasing cognitive effort. Functional connectivity and information transfer are metabolically expensive, but the incremental difference between tasks tends to be subtle. (PMC)

So the reason of reel-addiction does not lie in difference of energy consumed in the two tasks in question.

However, Reading recruits many distributed networks. Neuroimaging work shows deep reading (comprehension, visualization, semantic integration) engages broad language, semantic, memory and visual-imagery systems — i.e., many brain regions fire together. That implies heavier engagement of distributed networks (but not necessarily a hugely larger net metabolic bill). (Nature)
Short videos strongly activate sensory + reward circuits. Short, highly stimulating videos (reels/TikTok style) drive intense visual/auditory processing and the brain’s reward/attention systems — producing strong transient activation patterns and potentially different temporal dynamics (spikes of activity, habituation, dopamine/reward pathway engagement). That’s different circuitry from deep reading but doesn’t automatically mean overall greater calorie use. (PMC)

A more detailed breakdown of reasons is mentioned below:

The question of addition of masses to reels and no such phenomenon with reading books, gets at human neurobiology, evolution, technology, and economics all at once. Here’s the core idea:

Books were never engineered to create addiction. Short-form video feeds are.

Below is a clear explanation of why reels/tiktoks can create mass-scale addictive behavior, while books — despite existing for centuries — almost never do.

🔍 Human brains evolved for novelty, speed, and reward — not for deep reading

🧠 Evolutionary mismatch

The human brain evolved in environments where:

Novel, surprising information was rare
Quick detection of movement, faces, and emotions had survival value
Reward (especially dopamine-triggering events) was unpredictable and intermittent

Short videos exploit all three:

Quick motion & bright visuals → strong, ancient visual pathways
Human faces, emotional expressions → automatically grab attention
Surprise/novelty in every swipe → dopamine spike via variable reward

Books, by contrast:

Are slow
Require effortful decoding of symbols (文字 → meaning)
Deliver rewards only after sustained focus

Our brain defaults to the path of least resistance. Books require “System 2” effort; reels hijack “System 1” reflexes.

🚀 Reels use variable-reward loops — the same principle as slot machines

Every swipe is a gamble:

Sometimes: funny, sexy, shocking, inspiring, cute
Sometimes: boring
But you never know which is next

This variable-ratio reinforcement schedule is the most addictive reward schedule known, used in:

Casinos
Video games
Loot-box mechanics
Social media feeds

Books give predictable rewards: information, story progression. Predictable rewards don’t generate compulsive behavior the same way.

⚙️ Short video platforms are designed for addiction; books are not

TikTok, Instagram Reels, YouTube Shorts all use:

AI ranking optimized to maximize “time spent,” not satisfaction
Thousands of micro-interactions tracked per user
Real-time adaptive feedback loops tuned to your exact preferences
Instant delivery of content with zero friction (just a swipe)
Continuous novelty

Books have:

No algorithm
No real-time reinforcement
High initial friction (you must decide → open book → start effortful reading)
Slow feedback loops

Books are an old, static medium. Short-form video is an algorithmically optimized dopamine engine.

👫 Books activate deep cognition; reels activate reflex circuitry

Reading a book:

Language networks
Memory systems
Executive function
Imagination
Visualization
Long-term attention systems

Watching short videos:

Visual cortex
Auditory cortex
Salience network
Reward circuits (dopamine, novelty detection)
Social processing circuits (faces, emotions)

Deep cognition is not addictive. Rapid sensory + reward activation is.

📱 Accessibility and friction matter more than people realize

To read a book:

You need time
You must stay in one place
You must resist distractions
You must be somewhat rested

To watch reels:

Unlock phone → swipe
Endless, frictionless content
Works when tired, emotional, bored, or waiting 20 seconds

People are not addicted to reels because “humans changed.”People are addicted because friction dropped to zero.

🧪 Modern platforms exploit psychological vulnerabilities

Reels are optimized to exploit:

Boredom
Loneliness
FOMO
Dopamine-seeking
Social comparison
Emotional triggers
Sexual cues
Identity-based content
Outrage/curiosity loops

Books don’t adapt to your vulnerabilities. Reels do.

💰 Economic incentives: publishers sell books, tech companies sell attention

Books are sold once.

Platforms earn money every second you stay on the app.

Billions of dollars go into:

Behavioral scientists
UX researchers
Algorithm researchers
A/B testing
Addiction-optimization metrics

Nothing comparable has been invested in making books addictive — the incentives differ.

🌍 Scale & speed

Books rely on slow cultural diffusion.

Short video platforms:

Spread virally
Use network effects
Reach billions instantly
Shape norms of entertainment
Turn creators into constant suppliers of novelty

You cannot have 5 million new books per hour.But you do have 5 million new reels per day.

🔥 Putting it all together

Why reels create mass addiction:

Designed for dopamine
Instant variable rewards
Personalized by algorithms
Low friction
Highly stimulating
Emotionally rich
Leveraged by massive economic incentives
Perfectly aligned with primal brain circuits

Why books do not:

Slow
Require effort
High cognitive load
Low stimulus
No algorithmic reinforcement
No variable reward schedule

Books activate the “thinking brain.”Reels activate the “reward and survival brain.”

The latter wins almost every time unless you deliberately resist.

One of the above points may prominently catch one's attention -The activity of watching reels and short videos activates Primal Brain Circuits. On the other hand reading engages slow, effortful, high-level cognitive networks of brain. These circuits are anti addictive.

The above fact compels one to think that sustained mass addiction of short videos and reels has the potential to regress the cognitive functioning in large number of humans, since the older circuits of brain are more in use.

The studies further show that-

Reels heavily engage ancient brain systems and under-engage recent ones

The human brain has layers built over time:

Old systems (millions of years old)

reward circuitry (dopamine)
novelty detection
emotion & salience processing
fight/flight circuits
instinctive attention

New systems (tens of thousands of years old)

executive control
long-form attention
reflective thought
language-based reasoning
delayed gratification

Reels overstimulate the old systems and underuse the new ones.

That leads to:

decreased capacity for sustained attention
lower frustration tolerance
reduced deep-reading ability
difficulty processing complex ideas
heightened distractibility

This feels like regression because it shifts behavior toward the fast, impulsive, reactive brain, not the slow, deliberate, reflective brain.

Chronic short-form video consumption can:

weaken attentional networks
reduce working memory performance
shorten patience for low-stimulus tasks
elevate baseline dopamine-seeking
reduce sensitivity to subtle reward
impair deep-learning pathways

When these changes occur, people can:

find books “boring,”
lose ability to follow long arguments,
crave instant gratification,
avoid complex thinking,
struggle with boredom or silence.

Reels shift behavior toward older evolutionary brain systems at the expense of newer, human-defining cognitive abilities.

In that sense, — it is pushing human attention and cognition toward an evolutionarily older mode of functioning or Lower cognitive mode.

A more accurate phrasing

“Reels overactivate evolutionarily ancient reward and attention circuits while underactivating the newer circuits responsible for deep thought and self-regulation.”

This explains:

why reels feel addictive,
why reading feels harder,
why society seems more distracted,
why cognitive depth is decreasing in many populations.

🌉 A helpful analogy

Think of the human brain as a 3-story building:

Basement → ancient survival/reward circuits
Ground floor → emotional/social circuits
Top floor → reasoning, language, reflection

Reels:

light up the basement like fireworks
overstimulate the ground floor
make the top floor feel dull and “not worth the effort”

So people end up living on the lower floors more often.

Not because the top floor disappeared. But because the lower floors give cheap, fast, high-intensity stimulation.