Short-form video platforms like TikTok may negatively impact cognitive functions such as analytical thinking and prospective memory by reducing user agency and promoting passive consumption, though the long-term effects and the concept of "brain rot" require further research.
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In 2022, a lab in Munich did something
that I've been wanting to see. They gave
60 people a cognitive test, then sent
them away for a 10-minute break, and
then tested them again. [music] Now, the
difference was the break. Some people
just sat there, some scrolled on
Twitter, some watched a normal YouTube
video, [music] and some went on TikTok.
So, whose brain changed during that
time? This is one of the few experiments
that I've been able to dig up that has
actually tested the idea of [music]
brain rot. But the science is starting
to catch up to the fact that short form
video feeds are everywhere. [music] And
almost all of the commentary says that
they're making us dumber.
>> I cannot physically [music]
bring myself to study.
>> I'm addicted, too. We're all addicted to this.
this.
>> Oh, no. It's
>> horrible for you.
>> Oh, and we're giving kids just the
attention span of a walnut. This [music]
is awkward because we make shorts and it
has introduced us to a bunch of new
viewers. If Brain Rod is real, then we
might be part of the problem.
>> I do have a lot of skepticism whenever
there's a claim that like some new thing
is fundamentally changing the way that
humans operate.
>> Yeah. Apparently, Socrates thought that
writing was going to ruin our minds and
you know, people worried about novels
being addictive and the telegraph and
all of that. Like on Howtown, we don't
just take the conventional [music] wisdom.
wisdom.
>> We're not running on vibes over here.
We're trying to see if there's anything
behind the vibes.
>> So, I went hunting for evidence. We've
heard about shrinking attention spans
since the start of the smartphone era,
but how can we measure those? And what
are the studies saying about the video
feeds specifically? After 10 [music]
minutes of swiping through shorts, do
First, I wanted to know what makes this
new format different from the hours of
television that people watch every day.
And you can hear it in how the companies
talk about their own product. See, last
year, a bunch of private conversations
between Tik Tok employees came to light
after 14 US states investigated and sued
the company.
>> This is multiple lawsuits coming from
individual states attorney general, and
the action alleges that Tik Tok exploits
and harms young users. The state
attorneys had agreed to black out the
confidential materials, and I found the
breadth of these redactions odd. That's
a local reporter named Sylvia Goodman.
She discovered that the redactions in
the Kentucky complaint had not been done
correctly. I copy and pasted it all out
into a fresh document, and I could read
all of those redactions. I'll be honest,
my jaw was on the floor reading some of
this. The document showed Tik Tok
employees openly grappling with the
potential harm of the bold glamour
filter. bold glamour filter. This is
without the filter.
>> They admitted that those screen time reminders
reminders
were a good talking point, but not
altogether effective. One sentence that
really stood out to me came from an
internal document titled digital well-being.
well-being.
>> Tik Tok's success can largely be
attributed to strong out-of-the-box
personalization and automation, which
limits user agency.
>> We hear a lot about that
personalization. That's the famous
algorithm that decides what to show you
based on what you watch and what people
with similar watch behavior watch. But I
want to zero in on that last part about
how the interface limits user agency.
They're saying that Tik Tok wins by
making fewer things feel like your
decision. And I think that's the key to
understanding what short form video
feeds might be doing to our [music]
minds. And since we use that word feed,
let's roll with the food analogy. [music]
The restaurants we know have a menu. You
browse, you pick something, you eat it.
Streaming television is that kind of
restaurant. YouTube is too, or it was.
Their big innovation is that the menus
are personalized based on what you've
eaten there in the past.
Now, imagine a restaurant without menus
where you sit down, open your mouth, and
a device places a morsel of something
onto your tongue. You don't get another
bite until you eat it or spit it out. By
measuring your chew time, the restaurant
can adjust the lineup of bites to
feature more of the flavors that you
tend to swallow.
But they don't just hit you with the
same flavor time after time. They can
also test out some unexpected morsels
[music] because even if it's not your favorite,
favorite,
it's [snorts] just a bite. And there's
another one waiting that might be
amazing. Without a menu, you lose the
experience of choosing, but you gain the
experience of being surprised over and
over and over again.
Plus, a lot more people can make morsels
than can make a whole menu. So, this
restaurant can recruit way more cooks
trying way more tricks to make their
morsels tasty.
This restaurant is Tik [music] Tok and
reals and YouTube shorts and all of the
other imitators. and it is probably the
most engaging media interface that I've
ever seen. Just in terms of sheer
entertainment by watch time. There's a
catch, though. This sequential feeding
system wouldn't work if the dishes were
big or complicated. It only works with
morsels. If you take away the user's
agency, you arrive at short form. We've
seen this happen before with Tinder.
Instead of a dating app based on a menu,
they showed one profile at a time,
forcing feedback from the swiper. And
what happened? The profiles became short
form. Just photos, a couple of words,
and an algorithm that encodes our
subconscious responses more than our
reflective intentions. Maybe you noticed
that all the dating apps became Tinder.
So, is all of media becoming Tik Tok?
I've been trying to figure out just how
much human attention has shifted into
these feeds, but only the platforms know
that and they don't release the data.
But they do these quarterly calls with
investors. And if you go back through
the past few years, you can kind of hear
just how big of a response Meta and
YouTube have made to [music] the rise of
Tik Tok.
>> Reals already makes up more than 20% of
the time, 50% of the time that people
spend on Instagram.
>> Over 15 billion views each day. 30
billion billion plus 70 billion.
>> We now average over 200 billion daily
views on YouTube shorts.
>> Social media has gone through two eras
so far. First was when all content was
from friends, family, and accounts that
you followed directly. The second was
when we added all of the creator
content. Now, as AI makes it easier to
create and remix [music] content, we're
going to add yet another huge corpus of
content on top of those.
It's really easy for me to think of this
as the bowl of potato chips that someone
sticks on the table that you didn't
order, but it's there, so you snack on it.
it.
>> No one can eat just one. [music]
>> And it makes me wonder if How town
shorts are kind of like, do you know
those like pe-shaped potato chips?
>> Uh-huh. Right. Right. Right. I know what
you're talking about.
>> It's like a green Cheeto.
>> There's a version of this that's like,
but our chips are made of vegetables. I
suppose it's no surprise that a
bottomless personalized mystery snack
dispenser could take over our media
diets, but there is such thing as a
healthy snack, right? So, I'm going to
tell you about all the research that
I've read about this and then maybe we
can decide how we feel about it.
>> Yeah. Great. Yeah. It's interesting. As
you've been researching all this, I have
been feeling especially scatterbrained.
I'm like distracted by the news. I've
been moving between two different
continents. So, it's a happy coincidence
that the sponsor for this week's episode
is [music] Headspace, the mental health platform.
platform.
>> Did you try it?
>> Yeah. Yeah. They sent me a free
subscription and I've been taking their
finding focus course, which [music] is
basically 10-minute sessions of guided
meditation, and it's been really nice,
honestly, to have that break in my day.
A couple days ago, I actually just did
one while I was waiting for the bus. You
know, I've done a fair amount of
reporting on mindfulness meditation over
the years, and there's a real growing
body of evidence from some pretty robust
studies that it can improve your working
memory. It can improve your ability to
sustain attention. In one study, people
who meditated with headsp space for a
month were less distractable than a
control group who did these standard
brain training exercises, things like
puzzles and memory tasks. So, if you,
dear viewer, want to help your brain to
focus, you want to learn to meditate,
maybe you just want to have these calm
moments built into your day, you can
start Headspace for free by following
the link in our description box or
scanning this QR code that's on screen.
Usually, it's just a twoe trial, but
with this link, you get a full 60 days
completely free. Before we get to Tik
Tok, there's a bigger question to
answer. Have our attention spans really
shrunk? According to a 2015 post by Time
magazine, yes, they're now shorter than
a goldfish. But this is one of those
myths that won't die.
>> Here's a fun fact.
>> Some researchers have concluded that our
attention span is now shorter.
>> Shorter than a goldfish.
>> That's a scientific fact.
>> The claim came from a report published
by Microsoft which had this graphic
showing our attention span declining
from 12 seconds to 8 seconds. But they
were citing something called statistic
brain which in turn cited these sources.
And when journalists tried to track down
those sources, they didn't exist. The
numbers were entirely made up for both
the humans and the goldfish. So what
would it really take to measure
attention spans? Well, I talked to one
of the few people who have tried. My
name is Gloria Mark. She's written a
book called Attention Span. And way back
in 2003, she convinced an investment
management company to let her peek over
the shoulders of 14 of their employees
as they [music] worked.
>> And we would just observe them and with
stopwatches, every time they changed to
do something else, we would click on the
the stopwatch and [music] it was very,
very tiring. Those employees spent about
2 and 1/2 minutes working on their
computers before they switched to
checking email or doing something else.
[music] Fast forward to 2012. She
convinces another workplace to let her
install software that tracks [music] how
often their employees click from one
window to another and finds that they
switch every 75 seconds on [music]
average. Now it's closer to 40.
>> So yes, empirically we can say that on
screens attention spans have shortened.
>> It's a little tricky because obviously
we have this method switch like without
that dot at 2004 the trend doesn't look
as dramatic, right? It's sort of funny
to me to think about the adjudicators or
the watchers in that first test were
also having their attentions tested.
Like were they able to catch like
they're also having to focus? The other
big question I would have is like is
this measuring
our ability to focus or just how much
distracting stuff there is in our lives.
What I'm worried about is that I'm no
longer able to read a book for 6 hours
like I did when I was 12.
>> Has something changed about your brain?
>> Yeah. Has has something changed about
the ability of my brain? It's obvious to
me that something has changed about the
way that computers work. Like, yeah,
I've just got notifications. There's
literal sounds that are telling me you
should be distracted by this other thing
right now. And so, I still have I'm
still curious about like if there's
actual damage being done to our mental
systems. I guess
>> the advantage of Gloria Mark's approach
is that it captures real life. It's not
just bringing people into a laboratory,
having them sit for an hour in front of
a computer, but we actually observed
what people did over the day in the
course of their actual work. The
limitation is that it can't distinguish
between these three different influences
on our ability to focus. There's our
attentional capacity. That's what we
generally think of when we say attention
span. Then there's our motivation, how
much we need or care about focusing on
this task. And there's competition. How
much is our environment distracting us?
Now, in a lab, they can get closer to
controlling for motivation and
competition. But the tasks that they
give people don't look anything like
real life. Let me show you. This is a
classic attention test. They tell you to
memorize this image. And then you go
through these rows, crossing out the
items that match the one that you
memorized. You get 20 seconds per row.
There's 14 rows. They look at how many
errors you make, how fast you work,
whether you get worse over time. And on
this test, performance in adults has
actually been increasing. That's
according to a study that compiled
scores from three decades [music] and 32
countries. In children, overall
performance hasn't changed, but their
test taking style has. They've become
faster, making more errors, but also
completing more items. Now, researchers
who run lab tests like these don't claim
to be measuring attention span. I think
we often in daily life, and I even do
this myself, we just talk about
attention, and it feels obvious, like we
know what it means to pay attention, but
actually if we give people different
tasks, we can see that there's distinct
components of attention that aren't
necessarily related to each other.
>> Monica Rosenberg studies patterns of
brain activity during attention tests.
the same.
>> When I'm watching a really engaging
movie, like my lab collected data as
people watched a Hitchcock film and
YouTube videos about cooking, is this
the same kind of attention or is there
something fundamentally different about
right being engaged in a narrative that
I'm motivated to follow versus forcing
myself to do this boring task? Um, and
it, you know, it turns out there's some
similarities, but there's also some
differences. And so I think how well I
do on one task with pictures is not
indicative of how well I pay attention
all the time in all contexts. It's
certainly related, but it's not a
perfect measure. So let's set aside the
concept of attention spans. It's a
really fuzzy term. It's hard to measure.
The sharper question to ask is if you
binge short form video, what exactly
gets worse? Is it your memory? Your
reasoning? That's what the next few
studies are trying to pin down.
If you ask, do people who say they're
addicted to short form video also have
trouble focusing? So far, the answer to
that seems to be yes. A recent review of
14 studies found that increased SFV use,
that's short form video, was associated
with poorer cognition, including
attention and inhibitory control. But
whenever you see that term was
associated with that scientist code for
we're not saying this causes the problem,
problem,
>> right? It's sort of our social media and
teen health all over again where it's
are depressed teens becoming depressed
because they are on social media or are
they seeking it out?
>> Yeah, I think this is the question with
basically all of the harmful effects
that people are attributing to these new
technologies is almost all the research
can't distinguish correlation from
causation. But there are a few
experimental studies that I wanted to
highlight. There are at least two
different cognitive tests where people
perform worse after scrolling a shorts
feed. One is a kind of trick question
quiz and the other is about whether you
can remember to do something that you
plan to do. So first there's a measure
based on these three questions.
>> A bat and a ball cost $110 in total. The
bat cost $1 more than the ball. How much
does the ball cost?
This is supposed to capture analytical
thinking. To get these questions right,
you have to switch out of autopilot like
your gut is screaming
>> 10 cents and you need to override that.
72 college students at Ping University
in Beijing took this test after either
spending 30 minutes scrolling Tik Tok or
the Chinese version of Tik Tok or 30
minutes reading. And the Tik Tok group
did worse. The researchers wanted to
know does what you watch matter? So,
they ran a second study, but this time
people watched either a cute animals
playlist or a science experiments
playlist. They also changed how people
watch. Some could swipe through the
videos like a normal feed. Others had to
sit and watch the same clips stitched
together into one long video. And here's
what they found.
It didn't matter whether you watched
animals or science, but the swiping
groups consistently did worse on the
cognitive reflection test. They got 38
fewer questions right out of the three
questions total. That's 12% of the scale
after 30 minutes from just swiping alone.
alone.
>> Okay. Interesting. So, if you're you're
subjected to essentially just a montage
of videos that you don't have control
over, you are not degrading your
analytical thinking as much as if you're
swiping through and getting to just skip
whenever you are bored. It's sort of
interesting because you you think of
that decision is interacting with the
interface, right? That decision is
cognitively more intense than just
sitting back and letting something
happen to you, right?
>> Yeah. Unless boredom is cognitively
intense in a way that we don't recognize.
recognize.
>> Okay. So, that's one test that short
form video makes you worse at. The other
is a test of prospective memory, which
is when you remember to do something
that you intended to do, like picking up
the dry cleaning or joining a Zoom
meeting or taking a medication that
you're supposed to take. Researchers at
the University of Munich wanted to know
how short form video feeds affect that ability
ability
>> because it was coming from a general
observation that like if you scroll a
bit, you feel like don't want to say
that you feel like new, but like you
kind of
>> dissociate. Yeah. Yeah. Dissociated a
bit. So it was something like we said
okay is this actually really happening
like and we felt that. So we said okay
let's figure out uh how we can you know
make this uh solid user study and
investigate what can be a cognitive um
function that be associated.
>> So how would you test perspective memory?
memory?
>> Boy oh boy. Well it feels like yeah
we're getting tested all the time. If
you tell me to do something and then you
wait 30 minutes and see if I did it. Is
that long enough to be considered
perspective memory or does it have to be
like I know I have a meeting on
Wednesday at 1 and do you show up at the
meeting? Is that is there a time scale
involved in what is considered
perspective memory?
>> Yeah. Well, I mean the way that the way
that psychologists define it for their
purposes is is even much shorter than
that because
>> they need a way to measure it in the lab
>> with subjects that they don't have
access to for very long. So, the way
they try to capture perspective memory,
which is this idea of remembering a
previous goal or intention, is they
embed a task within a task. So, you're
going to try this out.
>> No. Great. I should have slept more last night.
night.
>> Fly sheet.
>> The subjects were told to press N on
their keyboard if the word on the screen
is a real word.
>> My heart is racing.
>> And M if it's a fake word. >> No.
>> No.
But if they saw the words blue, purple,
or green, they were supposed to press Q,
W, or E, respectively.
>> Purple is that's the perspective memory
[music] task.
>> Nope, I did it wrong. [laughter]
I got it wrong already. I already know. Houseman
Houseman
joust green. I love green. They had
people do this task and then take a
10-minute break in which they either
just rested, scrolled Twitter, watched a
YouTube video, or scrolled Tik Tok, and
then they took the test again. When they
compared the scores from before the
break and after the break, the
performance on the real word, fake word
task was the same. But for the blue,
purple, green task, where they needed to
remember that second intention, one
group saw a big drop in their scores. It
was the group that scrolled Tik Tok
during the break.
>> What this is basically getting at is if
you should be keeping something in mind,
you lose that with the scrolling behavior,
behavior,
>> but not just scrolling because Twitter
is a scroll behavior as well,
>> right? That's true. It's short form
video specifically.
>> That study took place in Germany, but I
was able to give this test to Adam in
English because researchers in the UK
replicated it in their own sample of 45
students. And this time they tested
different ways of watching short form
video. One group was limited to 10
swipes. The other group was allowed to
swipe as much as they wanted. And there
was a control group that just sat
quietly. The group that watched shorts
but was limited to 10 swipes didn't see
a drop in their performance. The
unlimited swiping group did. So again,
it's like
something about just being able to do this
this
mindlessly is is the problem. So, if
you're watching this in a clipped short,
don't swipe away.
>> Actually, what you should do is download
all the Howtown shorts, but watch them
in one big stream.
>> There you go.
>> Um, so that's basically where we're at
with this with the research. There's a
few of these experimental studies.
They're using a few different types of
cognitive tests, none of which really
map on to our popular conception of
attention span, but are related
cognitive skills. and they're raising a
few red flags, but obviously the the
caveats of small samples um and tasks
that are very different from our
[clears throat] everyday lives. Now, I
want to know if I'm scrolling TikTok
every night before bed for 2 hours, am I
just generally having a worst
perspective memory in my life, or is
that confined to just right after I use
it? long-term studies would actually
really inform uh and maybe guide better
ethics and policy in designing the
interface. I think this is actually
something that could really impact the
quality of life of people probably and
provide evidence that maybe something
has to change.
>> In 1890, the pioneering American
psychologist William James [music]
wrote, "My experience is what I agree to
attend to. My experience is what I agree
[music] to attend to. And there's more.
He said, "Only those items which I
notice shape my mind. Without [music]
selective interest, the consciousness of
every creature would be a gray chaotic indiscriminatic
my relationship to mangoes will never be
the fame. [music] And yet, I keep coming
back to this question of user agency or
what James called selective [music]
interest. Agency is at the heart of both
analytical thinking and perspective
[music] memory. Those weird little tests
are basically asking if your brain is on
autopilot [music] or if you can slow
down, make a turn, remember where you
intended to go. It's not just your
intentions that [music] get lost. Feeds
that nudge the customers into autopilot
tend to nudge the cooks [music] into
autopilot, too.
>> Scientists just created Here's what
would happen.
>> Scientist Here's what happened. Scientist,
Scientist,
>> but not everyone. Last time I checked,
Smarter Everyday, you guys had not
posted anything into the shorts feed. Is
that still the case?
>> That's the case. I have elected not to
do that because I don't think it's good
for [music] people. I don't think the
infinite scroll is healthy for our
minds. It's easy for me to say this
because Smarter Everyday has been around
for a while and there's a lot of really
awesome people that support the channel,
but I think saying no to shorts is
powerful. Um, [music] and I think it
ultimately increases trust in the
creator. Um, I could be wrong about
that, but I don't know. [music] That's
where I'm at.
>> Dustin's such a good guy. Um, yeah. I
mean, I think, you know, obviously we
want to be acting with integrity and
sort of like living our values in all
parts of our life, including the way we
make this channel, but like having
bite-sized information, you know, when I
was at NPR, we would make 3minut radio
pieces all the time, right? That was
like a pretty typical length. And I
didn't feel like those were bad for the
world just because it was a compressed
amount of information about a complex
subject. I thought like, oh, this is
good. Like someone is learning something
that they wouldn't otherwise know. The
question is, do we want to participate
in this in these endless scrolls?
>> I don't know if you see these comments
sometimes on our shorts. This one says
like, "Your contents are the most
anti-brain rot content [music] out
there. Actually, genuine and very high
quality." And then someone responded,
"No such thing as anti-brain rot [music]
content when it's short form."
>> So, that's basically kind of the
question that we need to answer.
>> Yeah. Yeah, that's right. Is there such
thing as a good short [music] uh as an
anti-brain rot short?
>> What do you think? Is this research
strong enough that we should be making a
change? Let us know in the comments. You
can also find more of my conversation
with Destin and hear Adam and I
processing all of this over on our
Patreon. And if you're interested in
meditation, which is arguably the
opposite of binging a shorts feed, click
the link in our description to try
Headspace free for 60 days. That deal
doesn't last. So try it now. See how
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