Study: Video Games Make Kids Smarter

Emily Oster

8 min Read Emily Oster

Emily Oster

Study: Video Games Make Kids Smarter

Unfortunately, probably wrong

Emily Oster

8 min Read

Today’s newsletter is a single-paper deep dive. I’m often reluctant to put this kind of focus on a single paper, especially one that isn’t (say) a large randomized trial. Today’s topic is the impact of screen time on IQ, and it’s an example of a problem where it frequently makes sense to look at the entire literature all at once. Focusing on one result can put overly much weight on just one set of data.

However: I think this particular paper is a useful one to talk through, since the methods are interesting, it illustrates some of the difficulties of addressing this question, and it starts by arguing the opposite of most of the literature.

The paper is here. The title: “The impact of digital media on children’s intelligence while controlling for genetic differences in cognition and socioeconomic background.” The headline finding: Exposure to video games is associated with faster intelligence growth over two years in late elementary school. Social media is neutral, and watching videos is also associated with faster intelligence growth.

The authors make much of the gaming finding especially, even saying early in the paper, “In specific, we had a strong expectation that time spent playing video games would have a positive effect on intelligence.” They theorize that the fast pace of the games pushes children to learn more quickly, or serves as a kind of “cognitive training.” The paper goes so far as to suggest that some of the overall increase in measured IQ over the past century (called the Flynn effect) is a result of video game and screen exposure.

This whole discussion — the statement of initial expectations, the findings, etc. — is really different from most of what the literature finds or focuses on. This is why it’s an interesting deep dive. The TL;DR of the below is that I do not think this paper makes a compelling case that video games are good for cognitive development, any more than other papers make the case that they are bad. Beyond that, it’s revealing about the big-picture issues in asking this question.

The paper and its findings

This paper tackles the question of whether exposure to media, in various forms, impacts measured IQ. The researchers approach this problem by using a sample of almost 10,000 children ages 9 and 10 who were studied in 2015 as part of the ABCD Study in the U.S. Children in the study were surveyed and asked about, among other things, their media consumption. Measures of IQ were collected both at baseline and, for about 5,000 of the children, at a two-year follow-up.

The basic approach in this paper is similar to that in much of the literature. The authors look at the relationship between IQ and reported media consumption. They differentiate among gaming, television watching, and social media.

When doing this analysis, the goal is to identify causal relationships in the data. This can be challenging. The first reason this is a hard problem is one I talk about a lot in the newsletter: differentiating correlation and causality. Media consumption habits differ across children for many reasons, and it’s hard to know if any differences in outcomes are due to media or to these other differences. This is true in the data used in this paper, too.

A central element of any paper of this type, at this point, is what approach the researchers will take to deal with these causality concerns. The most basic approach is to add more control variables — to adjust for more differences across family types. The authors here add two elements that they feel improve their inference: “polygenic scores” and exploiting changes over time.

The first innovation: the polygenic scores. Children in the study had genetic sequencing done. The authors use these genetic results to construct a genetic score that is predictive of IQ. They rely on existing published data that has shown some correlation between particular genetic polymorphisms and measured IQ — together, these “genetic scores” explain perhaps 10% of IQ variation. The authors’ argument is that by controlling for these, they are better able to adjust for possible confounding variation across children. Effectively, they see their analysis as calculating the impact of screen exposure on measured IQ, controlling for genetically predisposed IQ.

This is a cool idea, although it’s easy to overstate how valuable it is for identifying causal relationships. Two people with the same genetic score are not “identical,” so this isn’t equivalent to randomization. In my view, this factor improves the quality of their controls but does not fix causality issues.

The second innovation: changes over time. The primary analysis in the paper asks whether exposure to screens impacts the change in IQ from baseline to two-year follow-up. Their argument is that this effectively holds individual characteristics constant and allows them to isolate the impact of screen time.

I think this approach is confused. First, it is not at all clear why the causality issues that plague the analysis of IQ levels are made better in changes. The amount of screen exposure between the ages of 9 and 11 is also correlated with other aspects of family that probably affect learning over this period.

Second, this ignores any dynamic effects. Imagine (this is hypothetical) that screen time between the ages of 3 and 9 is very damaging but that between the ages of 9 and 11 it’s not as bad. The kids who have a lot of screen time between 9 and 11 very likely also had a lot of screen time between 3 and 9. But if the screen time is getting relatively less damaging, you would expect to see them catch up in test scores between 9 and 11. But not because screens are good! Looking at changes in test scores can make our estimates more precise, but they do not fix the causality problem in this case.

Digging into this paper, the most compelling result for me is the finding — toward the end — where the authors adjust for sibling fixed effects. Here, they are looking within families at differences in exposure and test scores. This goes much further toward controlling for family background than the polygenic scores. In that analysis, they do not observe any effect, positive or negative.

For me, that’s the takeaway from the data. I am not compelled by the arguments that gaming increases IQ. I find the sibling analysis, which shows no impact, to be the most compelling. I will say, apropos of where I started this post, that some of that feeling is informed by what I know from other papers. Generally, the effects of screen time on kids seem to be largely neutral.

Conceptual issues writ large

The above analysis is standard debunking. This is correlation and not causality, sibling fixed effects do it better, and so on. All perhaps useful if your instinct was to go out and buy a video game console to help your child achieve better in school.

But what I found more instructive about this paper is how it made me think about the difficulty of making any progress at all on these issues. One reason is that it highlights the tremendous interconnectedness here. The authors include a helpful (?) diagram illustrating how they see the mechanisms, which I’ve included below. Their interest in the paper is on identifying the impacts of screen time on the change in intelligence (their yellow lines). But simultaneously there are a million other things going on.

Baseline intelligence is impacting the change. Screen time is impacting the baseline. Socioeconomic status is impacting screen time and being impacted by screen time (that last is a bit unclear). Screen time is impacting itself (I am not precisely clear on that one either). It seems likely that these pathways all intersect. Not even considered here are the issues associated with selection in studies like this: the populations being studied may be different than the average. The bottom line is that identifying any one of these pathways, and separating it from the others, is just hugely difficult to think about.

A flow chart from a paper on video games.

The second conceptual issue is about alternative uses of time. I find it impossible to think about the impacts of gaming or TV watching or social media without thinking about what they crowd out. In the paper, the authors talk about the crowding out between these items. As in: maybe gaming looks good because it crowds out social media. But if we step back, we realize that any screen time here must crowd out something.

I’ve said this many times before, but it bears repeating that probably the biggest consideration with screen time is simply what else a person could be doing (more here). “Is video game playing good or bad?” is ill-defined without saying clearly what else someone would be doing with that hour or two.

In the end, this last point makes me pessimistic about ever answering with research the screen-time questions parents have. Even a randomized trial of particular types of screen time, or access to screen time, is going to be fraught if we do not understand well what the time is substituting for. Many of these choices are going to need to be made by relying on what we think works well for our family and, honestly, relying on our gut. Without much help from the data. Sometimes that’s just the reality.

A child's face is hidden by a glowing cell phone.

16 min read

Should My Kid Have Social Media?

How to navigate the goodÑand bad

Emily Oster
A parent and child make funny faces while taking a selfie in their living room.

Jun 08 2023

7 min read

How to Manage Your Family’s Relationship With Social Media and Smartphones

The past few weeks have seen a huge amount of discussion on social media and teens. This topic has been Read more

Emily Oster
A teddy bear is tucked under a pink sheet with an audio-only baby monitor.

Jun 16 2023

2 min read

Are Audio-Only Baby Monitors Worth It?

I’ve watched friends get addicted to watching their little ones on video monitors and feel like it can impede taking Read more

Emily Oster

Nov 16 2023

18 min read

How to Weigh the Risks of Social Media

Today’s podcast episode is a big one. I got a chance to sit down with the U.S. Surgeon General, Dr. Read more

Emily Oster

Instagram

left right
The AAP’s guidelines recommend sleeping in the same room as your baby “ideally for the first six months.” However, the risk of SIDS is dramatically lower after four months, and the evidence in favor of the protective effect of room sharing is quite weak (both overall and even more so after four months). There is also growing evidence that infants who sleep in their own room by four months sleep better at four months, better at nine months, and even better at 30 months.

With this in mind, it’s worth asking why this recommendation continues at all — or at least why the AAP doesn’t push it back to four months. They say decreased arousals from sleep are linked to SIDS, which could mean that babies sleeping in their own room is risky. But this link is extremely indirect, and they do not show direct evidence to support it.

According to the data we have, parents should sleep in the same room as a baby for as long as it works for them! Sharing a room with a child may have negative impacts on both child and adult sleep. We should give families more help in navigating these trade-offs and making the decisions that work best for them.

#emilyoster #parentdata #roomsharing #sids #parentingguide

The AAP’s guidelines recommend sleeping in the same room as your baby “ideally for the first six months.” However, the risk of SIDS is dramatically lower after four months, and the evidence in favor of the protective effect of room sharing is quite weak (both overall and even more so after four months). There is also growing evidence that infants who sleep in their own room by four months sleep better at four months, better at nine months, and even better at 30 months.

With this in mind, it’s worth asking why this recommendation continues at all — or at least why the AAP doesn’t push it back to four months. They say decreased arousals from sleep are linked to SIDS, which could mean that babies sleeping in their own room is risky. But this link is extremely indirect, and they do not show direct evidence to support it.

According to the data we have, parents should sleep in the same room as a baby for as long as it works for them! Sharing a room with a child may have negative impacts on both child and adult sleep. We should give families more help in navigating these trade-offs and making the decisions that work best for them.

#emilyoster #parentdata #roomsharing #sids #parentingguide
...

It was an absolute pleasure to be featured on the @tamronhallshow! We talked about all things data-driven parenting and, in this clip, what I call the plague of secret parenting. To balance having a career and having a family, we can’t hide the fact that we’re parents. If mothers and fathers at the top can speak more openly about child-care obligations, it will help us all set a new precedent.

Watch the full segment at the link in my bio 🔗

#tamronhall #tamronhallshow #emilyoster #parentingsupport #workingparents

It was an absolute pleasure to be featured on the @tamronhallshow! We talked about all things data-driven parenting and, in this clip, what I call the plague of secret parenting. To balance having a career and having a family, we can’t hide the fact that we’re parents. If mothers and fathers at the top can speak more openly about child-care obligations, it will help us all set a new precedent.

Watch the full segment at the link in my bio 🔗

#tamronhall #tamronhallshow #emilyoster #parentingsupport #workingparents
...

Invisible labor. It’s the work — in our households especially — that has to happen but that no one sees. It’s making the doctor’s appointment, ensuring birthday cards are purchased, remembering the milk.

My guest on this episode, @everodsky, has come up with a solution here, or at least a way for us to recognize the problem and make our own solutions. I’ve wanted to speak with Eve for ages, since I read her book Fair Play. We had a great conversation about the division of household labor, one I think you’ll get a lot out of!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#emilyoster #parentdata #parentdatapodcast #parentingpodcast #householdtips #fairplay #invisiblelabor

Invisible labor. It’s the work — in our households especially — that has to happen but that no one sees. It’s making the doctor’s appointment, ensuring birthday cards are purchased, remembering the milk.

My guest on this episode, @everodsky, has come up with a solution here, or at least a way for us to recognize the problem and make our own solutions. I’ve wanted to speak with Eve for ages, since I read her book Fair Play. We had a great conversation about the division of household labor, one I think you’ll get a lot out of!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#emilyoster #parentdata #parentdatapodcast #parentingpodcast #householdtips #fairplay #invisiblelabor
...

Prenatal vitamins 💊 If there is any product that seems designed to prey on our fears, it’s this one. You’re newly pregnant and you want to do it right. Everyone agrees you need prenatal vitamins, so you get them. But do you want to be that person who just… buys the generic prenatal vitamins?

Good news: fancier vitamins are not better.  Folic acid is the most important prenatal ingredient. Iron (with vitamin C) and DHA are also nice to have. Other included ingredients have only weak or no evidence to support their use. (If you do not consume animal products, add B12, plus a few others depending on your diet.)

Vitamins are just vitamins. Any prenatal vitamin that contains these is enough. 

Comment “Link” for a DM to an article with everything you need to know about prenatal vitamins.

#emilyoster #parentdata #prenatalvitamins #pregnancydiet #pregnancytips

Prenatal vitamins 💊 If there is any product that seems designed to prey on our fears, it’s this one. You’re newly pregnant and you want to do it right. Everyone agrees you need prenatal vitamins, so you get them. But do you want to be that person who just… buys the generic prenatal vitamins?

Good news: fancier vitamins are not better. Folic acid is the most important prenatal ingredient. Iron (with vitamin C) and DHA are also nice to have. Other included ingredients have only weak or no evidence to support their use. (If you do not consume animal products, add B12, plus a few others depending on your diet.)

Vitamins are just vitamins. Any prenatal vitamin that contains these is enough.

Comment “Link” for a DM to an article with everything you need to know about prenatal vitamins.

#emilyoster #parentdata #prenatalvitamins #pregnancydiet #pregnancytips
...

When it comes to introducing your newborn to the world, timing matters. It’s a good idea to minimize germ exposure in the first 6-8 weeks; after that, it’s inevitable and, very likely, a good idea! This doesn’t mean you need to be trapped inside. The most significant exposure risks are from seeing other people at home — family, etc. These interactions are not infinitely risky, but they do pose more risk than a walk or a trip to the grocery store, since they involve closer interaction. Think simple and make sure everyone is washing their hands before holding the baby. 💛

#parentdata #emilyoster #newborncare #parentingadvice #parentingtips

When it comes to introducing your newborn to the world, timing matters. It’s a good idea to minimize germ exposure in the first 6-8 weeks; after that, it’s inevitable and, very likely, a good idea! This doesn’t mean you need to be trapped inside. The most significant exposure risks are from seeing other people at home — family, etc. These interactions are not infinitely risky, but they do pose more risk than a walk or a trip to the grocery store, since they involve closer interaction. Think simple and make sure everyone is washing their hands before holding the baby. 💛

#parentdata #emilyoster #newborncare #parentingadvice #parentingtips
...

The first edition of Hot Flash is out now! Comment “Link” for a DM to learn more about the late-reproductive stage.

There are times when we expect hormonal shifts. Our reproductive lives are bookended by puberty and menopause. We discuss those changes often because they are definitive and dramatic — a first period is something many of us remember clearly. But between ages 13 and 53, our hormones are changing in more subtle ways. During the late-reproductive stage (in your 40s), you can expect a lot of changes in your menstrual cycle, including the length and symptoms you experience throughout. It’s an important time in our lives that is often overlooked!

🔥 Hot Flash from ParentData is a weekly newsletter on navigating your health and hormones in the post-reproductive years. Written by Dr. Gillian Goddard, Hot Flash provides all of the information you need to have a productive, evidence-based conversation about hormonal health with your doctor.

#emilyoster #parentdata #hotflash #perimenopause #womenshealth

The first edition of Hot Flash is out now! Comment “Link” for a DM to learn more about the late-reproductive stage.

There are times when we expect hormonal shifts. Our reproductive lives are bookended by puberty and menopause. We discuss those changes often because they are definitive and dramatic — a first period is something many of us remember clearly. But between ages 13 and 53, our hormones are changing in more subtle ways. During the late-reproductive stage (in your 40s), you can expect a lot of changes in your menstrual cycle, including the length and symptoms you experience throughout. It’s an important time in our lives that is often overlooked!

🔥 Hot Flash from ParentData is a weekly newsletter on navigating your health and hormones in the post-reproductive years. Written by Dr. Gillian Goddard, Hot Flash provides all of the information you need to have a productive, evidence-based conversation about hormonal health with your doctor.

#emilyoster #parentdata #hotflash #perimenopause #womenshealth
...

There are plenty of reels telling you how to parent. Plenty of panic headlines saying that “studies show” what’s best for your kid. Even good data, from a trusted source, can send us into a spiral of comparison. But I want you to remember that no one knows your kid better than you. It’s important to absorb the research, but only you will know the approach that works best for you and your child. 💙

Now tell me in the comments: what’s a parenting move you’ve made recently that feels right to you?

#parentingcommunity #parentingsupport #parentingquotes #emilyoster #parentdata

There are plenty of reels telling you how to parent. Plenty of panic headlines saying that “studies show” what’s best for your kid. Even good data, from a trusted source, can send us into a spiral of comparison. But I want you to remember that no one knows your kid better than you. It’s important to absorb the research, but only you will know the approach that works best for you and your child. 💙

Now tell me in the comments: what’s a parenting move you’ve made recently that feels right to you?

#parentingcommunity #parentingsupport #parentingquotes #emilyoster #parentdata
...

Let’s talk about sex (after) baby! Today on the podcast, I was lucky enough to speak with @enagoski about her new book on sexual connection in long-term relationships. Especially after having kids, this is something many people struggle with. Emily tells us to stop worrying about what’s “normal” and focus on pleasure in its many forms.

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #parentdatapodcast #emilyoster #emilynagoski #comeasyouare #cometogether #longtermrelationship #intimacy #relationships

Let’s talk about sex (after) baby! Today on the podcast, I was lucky enough to speak with @enagoski about her new book on sexual connection in long-term relationships. Especially after having kids, this is something many people struggle with. Emily tells us to stop worrying about what’s “normal” and focus on pleasure in its many forms.

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #parentdatapodcast #emilyoster #emilynagoski #comeasyouare #cometogether #longtermrelationship #intimacy #relationships
...

Ever wondered if you can safely use leftover baby formula? 🍼 The CDC says to throw out unused formula immediately because of the risk of bacterial growth. However, research suggests that bacterial concentrations do not appreciably increase after 3, 12, or even 24 hours at refrigerator temperatures. Good news! This means there’s not a strong data-based reason to throw out formula right away if you store it in the fridge.

Comment “Link” for a DM to an article on another common formula question: should you throw away old formula powder?

#emilyoster #parentdata #babyformula #babyfeeding #parentingstruggles

Ever wondered if you can safely use leftover baby formula? 🍼 The CDC says to throw out unused formula immediately because of the risk of bacterial growth. However, research suggests that bacterial concentrations do not appreciably increase after 3, 12, or even 24 hours at refrigerator temperatures. Good news! This means there’s not a strong data-based reason to throw out formula right away if you store it in the fridge.

Comment “Link” for a DM to an article on another common formula question: should you throw away old formula powder?

#emilyoster #parentdata #babyformula #babyfeeding #parentingstruggles
...

What’s the most important piece of advice for new parents? Here’s one answer, but I want to hear from you! Share your suggestions in the comments ⬇️

#emilyoster #parentdata #parentingtips #parentingadvice #newparents #parentingcommunity

What’s the most important piece of advice for new parents? Here’s one answer, but I want to hear from you! Share your suggestions in the comments ⬇️

#emilyoster #parentdata #parentingtips #parentingadvice #newparents #parentingcommunity
...

What's in the bag of a Vagina Economist? 👀 Someone please tell me this looks familiar to you.

What`s in the bag of a Vagina Economist? 👀 Someone please tell me this looks familiar to you. ...

Comment ”link” for a DM to learn more about tongue ties 🔗

Breastfeeding is often difficult, especially at the start. For babies with tongue ties, many infants (and their moms) struggle to get the hang of a good latch. This can lead to painful nipples and to inefficient feeding, and then low weight gain.

So what does the data say about the increasingly common practice of cutting tongue-ties in infants to improve breastfeeding success? Several weeks ago, @nytimes published a long and quite scary article on this topic.

After diving into the data, here is what I found. There is limited evidence that frenotomy procedures improve breastfeeding efficacy and the harms of the procedure are minimal. Many women do report that it alleviates pain and helps them with breastfeeding. However, it should not be a first-line treatment for breastfeeding problems.

#parentdata #emilyoster #tonguetie #tonguetiebabies #breastfeedingsupport

Comment ”link” for a DM to learn more about tongue ties 🔗

Breastfeeding is often difficult, especially at the start. For babies with tongue ties, many infants (and their moms) struggle to get the hang of a good latch. This can lead to painful nipples and to inefficient feeding, and then low weight gain.

So what does the data say about the increasingly common practice of cutting tongue-ties in infants to improve breastfeeding success? Several weeks ago, @nytimes published a long and quite scary article on this topic.

After diving into the data, here is what I found. There is limited evidence that frenotomy procedures improve breastfeeding efficacy and the harms of the procedure are minimal. Many women do report that it alleviates pain and helps them with breastfeeding. However, it should not be a first-line treatment for breastfeeding problems.

#parentdata #emilyoster #tonguetie #tonguetiebabies #breastfeedingsupport
...

Tag a friend who needs to hear this 💛 For many choices in parenting, there is no one right answer. We can use research and data to make informed decisions, but ultimately, it won’t tell you what to do. Only you can decide what will be best for your kids and your family.

I’m here to remind you to take a deep breath and trust yourself. I’ll be here to support you along the way. 

Thank you to everyone who submitted videos, including:
@sarah.consoli
@jess_lynn627
@nicolevandenwills
@thedrblair
@ncbenedict29
@haleycimini
@iamkellysnodgrass
@calesse_smith
@garnet__gordon
@jencoopgaiser87
@danigirl18c
@jamielundergreen
@carly_comber
@thecelebratingmama
@emilyannbynum
@eeliz413

#emilyoster #parentdata #parentingadvice #parentingsupport #parentingquotes

Tag a friend who needs to hear this 💛 For many choices in parenting, there is no one right answer. We can use research and data to make informed decisions, but ultimately, it won’t tell you what to do. Only you can decide what will be best for your kids and your family.

I’m here to remind you to take a deep breath and trust yourself. I’ll be here to support you along the way.

Thank you to everyone who submitted videos, including:
@sarah.consoli
@jess_lynn627
@nicolevandenwills
@thedrblair
@ncbenedict29
@haleycimini
@iamkellysnodgrass
@calesse_smith
@garnet__gordon
@jencoopgaiser87
@danigirl18c
@jamielundergreen
@carly_comber
@thecelebratingmama
@emilyannbynum
@eeliz413

#emilyoster #parentdata #parentingadvice #parentingsupport #parentingquotes
...

Congratulations on making it through another year of panic headlines! We’ve had some doozies this year, like aspartame causing cancer and the perils of white noise, but these headlines are very often based on poor data. Correlation does not equal causation. There will certainly be more panic headlines in 2024, but ParentData is here to debunk them for you.

#emilyoster #parentdata #happynewyear2024 #panicheadline #datadriven

Congratulations on making it through another year of panic headlines! We’ve had some doozies this year, like aspartame causing cancer and the perils of white noise, but these headlines are very often based on poor data. Correlation does not equal causation. There will certainly be more panic headlines in 2024, but ParentData is here to debunk them for you.

#emilyoster #parentdata #happynewyear2024 #panicheadline #datadriven
...