Debunking 6 Popular Psychology Myths

Short of time? Read the key takeaways.

💪 Willpower doesn’t seem to run on a single, depleting resource. Although hundreds of studies once supported ego depletion, many failed to replicate during the replication crisis. What remains is ordinary fatigue, boredom, and frustration, not strong evidence for a special self-control reservoir.

🎧 Tailoring education to “learning styles” probably doesn’t boost learning much. Despite its popularity, high quality studies rarely find strong benefits from matching teaching methods to auditory, visual, or kinesthetic preferences. If differences exist, they appear small, and visual memory may help most people.

📅 It doesn’t take 21 days to build a habit. That claim likely traces back to a plastic surgeon’s anecdote, not habit research. Habit formation varies widely and depends more on repetition, reliable triggers, consistency, and rewards than on a fixed number of days.

🔀 Humans sometimes can multitask, and sometimes can’t. Tasks that rely on different cognitive systems, or where one task becomes automatic, can be paired successfully. But two demanding conscious tasks, like following an audiobook while debating, tend to interfere with each other.

🕺 Power posing is neither transformative nor total nonsense. Early claims about hormonal and behavioral changes did not replicate well. However, larger studies suggest small boosts in perceived power and mood, meaning it may offer a mild, temporary psychological lift.

🎹 It doesn’t universally take 10,000 hours to become an expert. The idea oversimplifies research on deliberate practice. Skill level depends on complexity, competition, aptitude, and diminishing returns. Practice matters, but it explains only part of the variation in high performance.

There are many popular misconceptions about the way the mind works and about

human psychology. So today we're going to talk about:

• Popular misconceptions about psychology

• What the science really says

• Why people believe these things

And if (despite being a misconception) a theory actually contains a significant grain of truth, we'll talk about that too. What’s more, you can choose your own adventure: either read the newsletter version, below, or watch the video version of this newsletter by clicking here.

Myth 1: Willpower Is Like a Muscle (Ego Depletion)

Is willpower like a muscle that gets tired out as you use it? There's a popular theory, known as ego depletion, that says that self-control draws on a finite resource. So, as you exert self-control (for instance, deciding not to eat that cupcake and eat that vegetable instead), it's drawing on this finite resource, which means you have less available later on. So, afterward, if you're trying to decide between reading this intellectual book or simply doom-scrolling, you're likely to go with doom-scrolling because you're out of this finite resource of self-control. 

Why do people believe in this? Well, there's a really clear answer: It's because there are literally hundreds of studies about it, and they either show it's real or they treat it as though it's a real effect, and then they go study properties of it. But there is a big problem: the research seems to be bullshit. When people go and try to redo some of the major studies from scratch, carefully checking their work, they find that they don't get the same effect. In other words, a bunch of the classic findings seem to be false positives. 

Now, think for a moment about how crazy that is. Hundreds of scientific studies seem to either find an effect or study that effect, and yet the effect doesn't seem to exist at all.

To understand how this could possibly be the case, we have to understand the ‘replication crisis’ in social science. Studies more than 15 years ago were very commonly run using not very robust methods. So people would get statistical significance, but the study wouldn't hold up if someone were to replicate it. And replication was very rare. So it was very easy to get away with this for a long time. 

Thankfully, progress has been made. Methods have improved. The field is not yet where it needs to be, but it is making significant gains towards doing more robust research. We have a project called Transparent Replications where we replicate new papers in top psychology journals to see if they actually hold up to scrutiny. This allows us to see where the field is right now and to give recommendations for how to make it better. 

But does this mean that ego depletion actually maps onto nothing at all? Well, I'm not so sure. It sounds a lot like normal fatigue, boredom, or frustration that many people are used to when they have to exert willpower or make many decisions in a row. I think that often people have an experience when planning a wedding that by the 400th decision, where they're deciding about napkins or whatever, they're just phoning it in. They're so bored or tired or frustrated that they actually struggle with decision-making at that point. But it doesn't mean that ego depletion theory is correct or adds much to the story. We do get fatigued the more we do things, but we don't need a fancy theory to tell us that. 

Myth 2: People Learn Better When Education is Tailored to Their Learning Style 

You've probably heard of the idea of learning styles. The concept that some people are auditory learners, some visual learners, and some kinesthetic learners. You may even have had teachers that try to integrate this into the classroom when growing up. But why do people believe this is true?

Well, I think on the one hand, they have personal experience. They think, “For me, it's easier to learn visually, so I'm a visual learner.” On the other hand, I think there's a (mis)conception that there's a lot of scientific evidence about this, that this is something that's been proven. Ironically, the opposite is true.

There's a surprising lack of experiments demonstrating that you can actually get people to learn better by matching the content to their learning style. And interestingly enough, for most people, there is evidence that the visual part of the brain actually is better at remembering things than other types of processing. For example, we can see this with professional memorizers. They'll leverage the visual part of the brain by assigning interesting and bizarre visualizations to things. By leveraging our visual memory, we often can remember things better. 

There may also be an element of what we like learning because the things we learn kinesthetically through body movement tend to be different sorts of things than the things we learn visually or auditorially. That means if someone says they're a kinesthetic learner, maybe it just means that they gravitate towards, enjoy, and are good at the sorts of things you learn with your body. So, does this mean that we've proven that learning styles don't exist? 

Well, science can often struggle to prove a negative. For example, let's suppose you designed an experiment where you developed three versions of all your curricula. You measured students’ learning styles. You then had one group that got matched to the learning style content appropriate for them. And you had another group that got randomized content that didn't match their learning style. And you compared the two groups, and you showed no effect. Well, someone could just say your assessment for learning styles wasn't accurate enough, or you didn't do a good enough job with the curriculum design, or your auditory learning content wasn't as good as your visual learning content, and that created a weird confound in the result. 

So while it could be the case that people of different learning styles learn faster with different curricula that are suited for them, it seems likely that if there are such differences, they're quite small on average because if they were large, studies very likely would have found them by now. And the fact that they haven't so far in high-quality studies means they probably either don't exist or show just small differences. However, all it takes is one really well-done study that shows learning styles help to potentially overturn the current state of affairs.

Myth 3: It Takes 21 Days to Build a Habit

It takes 21 days to build a habit, right? Well, first, let's clarify what a habit is. When speaking technically, a habit is a behavior that has become subconscious. So, when there's a trigger, you do the behavior without even thinking about it. Often this is confused with a routine, which is something you do regularly, for example, at a particular time or a particular place, but there's a conscious element. You're choosing to do it, like you read the newspaper every Sunday morning. 

So now that we can distinguish between habits and routines, let's go back to that claim: “It takes 21 days to form a habit.” Where does that actually come from? Well, it's hard to know absolutely for sure where it came from. The most likely provenance is a plastic surgeon named Maxwell Maltz, who was writing about how long it would take his patients to get used to their surgical changes. He suggested that it was about 21 days. 

Now, it’s worth pointing out:

• One, this wasn't about habits! Already, that's a huge problem. 

• Two, this wasn't even a study. It was just his anecdotal observations.

But, somehow, it seems that this idea stuck - and it stuck with habits in particular, as though all types of getting used to things or changing would take the same amount of time.

So, that's a ridiculous origin story. And obviously, this doesn't provide good evidence that it takes 21 days to change. 

On the other hand, 21 days is a pretty reasonable estimate. It doesn't seem crazy. If you said habits occur after 1 day, most people wouldn't believe that. And if you said it takes 300 days, I think most people would think that’s too long. So I think part of why this sticks is probably that it's a pretty plausible estimate. So we don't immediately get skeptical. 

So how long does it actually take to form new habits? Well, research that looks into this finds that it's pretty variable. Sometimes it's 30 days, sometimes it's 100 days. It really can vary. But what does it vary based on?

I think it's much more useful thinking in terms of number of repetitions rather than number of days. So for example, let's suppose you wanted to form a habit that every time you walk into your kitchen, you drink a glass of water. Well, you might actually go into your kitchen quite a few times a day. Suppose that it's seven times a day on average. Well, that means you have seven repetitions every single day to practice that habit. And if for the first, let's say, 3 days, you never miss it a single time, you now have 21 practice sessions, you might actually be able to form the habit after just 3 days because you have enough practice sessions. 

On the other hand, if you often miss the trigger, let's say only half the time during those first three days when you go in the kitchen, you drink a glass of water. You're not going to reinforce the habit as effectively. And it might be flimsier. It might take more days to get put in place. 

So, how long does it actually take to form a new habit? Well, it's going to depend on:

• How many practice sessions you get in

• How reliably you do the habit when you see the trigger

• How consistent the trigger is (e.g., if you're in someone else's kitchen, sometimes it might be harder to form the habit because you don't have a consistent stimulus)

• And, if there's a reward, that can make the habit develop faster (e.g., if you really enjoy drinking water, then maybe the habit will develop faster than if you don't like the taste of water and you find it repugnant)

Myth 4: Humans Can (or Can’t) Truly Multitask

Let's talk about multitasking. You probably have heard the claim that multitasking makes people more efficient. But you might have heard the contrary claim that actually, multitasking is impossible. 

On the one hand, almost everyone has had some experience of successful multitasking. Maybe you were working out while listening to your favorite podcast, and that worked totally fine. On the other hand, there are some very interesting scientific studies that show that some types of multitasking simply don't work. If you were trying to listen to an audiobook and understand it while holding a conversation on a separate topic, it's nearly impossible. So, what's going on here? 

Well, certain types of tasks actually can be paired together; you can multitask them. Other types of tasks you can't do this for, though. So what's the difference? Well, usually when we can multitask successfully, it's because we can push one of the tasks into the subconscious. In fact, this is a critical concept in skill development for many skills. For example, if you've been driving for many years, there's a pretty good chance that most of your driving is actually subconscious. So you might be able to listen to a podcast at the same time and do so successfully. Now, that could degrade your performance if you suddenly have to make a conscious decision while driving. If you get into a tricky situation and you have to decide what to do, the fact that you're listening to a podcast might actually slow that down. But as long as you're doing driving that stays in the subconscious realm, you're going to be able to do something else at the same time. 

Myth 5: ‘Power Posing’ Works (or Is Total Nonsense)

You've probably heard the claim that power posing (adopting postures like the ones in the image below, which make you look powerful), could actually change your behavior for the better.

Now, the reason people believe this is actually really clear. It's because one of the most popular TED talks of all time claimed that power posing works, and the video was actually based on a study that the author conducted. Unfortunately, as people dug into the research, they saw that it was seriously methodologically flawed. And others who tried to replicate it had trouble replicating some of the findings, like changes in cortisol levels or changes in risk-taking behavior. 

But as we were digging into the research on this, we noticed something really interesting.  While it's true that the replications didn't tend to find those other effects like risk-taking, they did sometimes report increased feelings of power. In other words, participants felt an increase in power or a rise in mood after doing power posing. It didn't always occur in the studies, but it sometimes did. This got us wondering, could the effect actually be real, but just really small? So, we actually ran what at the time was the largest ever study on power posing. We randomized people. So, some did power poses, some did neutral positions, and some did low power positions, and we looked at their feelings of power and their mood, before and after. 

So, what did we find? Well, we found that power posing did increase people's sense of perceived power and how good they felt at the time. That being said, the effects are very small. So, whereas in the original claims, it seemed that this would be life-changing, in reality, it's a pretty mild effect. But if you just want to feel a little more powerful, for example, before going on stage, or you just want to give yourself a quick mood boost, you could try a power pose and see if it works for you.

Myth 6: It Takes 10,000 Hours To Become An Expert

It takes 10,000 hours of practice to become a world-class expert. Or does it? Why do people believe this? Here, we actually have a really clear story. It's from Malcolm Gladwell's phenomenally popular book, Outliers, where he summarized the research of Anders Ericsson about how it takes 10,000 hours of deliberate practice to become a world-class expert at complex skills like playing music. 

But there's a problem here. Anders Ericsson himself denies that this is an accurate characterization of his own research. The reality is it's cherry-picking and oversimplifying. For instance, if Gladwell had looked into international pianists, he might have found that it takes more like 20,000 hours for them to start winning international competitions that typically occur around the age of 30. The amount of practice we need actually varies based on the complexity of the skill and also how competitive the field is. If it's a field where there aren't that many competitors, it may take less practice. If it's a less complex skill, it will also take less practice. 

What we know is that with all skills, there's diminishing marginal return. When you're first learning a new skill, you get better very, very quickly, and then it starts to taper off. When you're at 10,000 hours, for almost every skill, you're going to be very deep in the marginal benefit. So, every additional hour is going to cause very little improvement. 

We also know that aptitude matters. While just about anyone can get better at just about any skill by practicing, some people are going to improve a lot faster. For example, if you don't learn perfect pitch by a young enough age, you'll probably never learn it, and that will be a disadvantage for certain types of musical tasks compared to people who do have it. Or if you're born with, let's say, dyslexia, that's going to make it harder to learn certain types of tasks. Yes, you can work around it, but you're going to be at a disadvantage, and it might take you more hours to get to the same level because of that disadvantage. 

There's some interesting research in the sports domain that tells us about deliberate practice and performance. They find that there's a 0.43 correlation between how many hours people do deliberate practice and how good they are at their sports. So that's not nothing, that's substantial, but it leaves a lot of variability unexplained by deliberate practice. Even more intriguingly, they found that in the most elite athletes, there's almost no correlation between deliberate practice and their ability. This makes sense because there are diminishing returns to practicing. At the very elite levels, other things besides the number of hours practiced might matter more, like how exactly they practice, what techniques they use, and so on. 

But why?

Why do so many psychological misconceptions exist in the first place? I think sometimes it stems from our own intuitions. We feel that something works a certain way, and then we tend to believe it even though it might not actually be right. Think about this compared to physics. We have an intuitive sense of how physics works, but experiments sometimes show that that's not the way things really work. When you get into really big things, for example, or really small things, we find that physics violates our intuitions. But another big reason why we have a lot of psychological misconceptions is that sometimes people put these ideas out there that are false, but they get a lot of attention for them. If they get millions of eyeballs, the idea spreads even if it's not true. And in fact, sometimes it not being true helps it spread because it's a nice, simple, and exciting story about what is truly a complex and nuanced topic.

If you're interested in psychological misconceptions, check out our Transparent Replications project, where we go replicate new papers coming out in top psychology journals when we say, "Are they actually true? And if not, what went wrong in the research?" 

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