Statistical Significance—and Why It Matters for Parenting

Emily Oster

3 min Read Emily Oster

Emily Oster

Statistical Significance—and Why It Matters for Parenting

Fake studies, p-hacking, publication bias, and more

Emily Oster

3 min Read

One of my big goals with ParentData is to enhance data literacy. Yes, I want to be here to talk you down from the panic headlines you read. But I also want to give you the tools to talk yourself down, at least some of the time.

Today, we’re doing data literacy. I’m going to talk about statistical significance

The phrase “statistically significant” is probably one most people are familiar with, or have read before. Media coverage of academic results will often use it — as in, “In this study, the relationship was statistically significant.” When it is used in common parlance, I think people often read it as meaning “true.” This phrase somehow implies that the result is right, or real. 

One reason that this conclusion might be wrong, of course, is that a lot of studies estimate correlations, not causal relationships. That’s an issue I discuss all the time. There is a second issue, though, which is what I’ll be going into here. Even in an experiment — where we have a randomized treatment, so we are more confident that the results we see are causal — understanding what the results mean requires a real understanding of statistical significance.  

That’s our job for today. No bottom line on this one — you’ve got to read it! But if you get to the end, there is some funny stuff about a dead fish, so hang in there.

What does “statistically significant” mean?

When we say an effect is “statistically significant at the 5% level,” what this means is that there is less than a 5% chance that we’d see an effect of this size if the true effect were zero. (The “5% level” is a common cutoff, but things can be significant at the 1% or 10% level also.) 

The natural follow-up question is: Why would any effect we see occur by chance? The answer lies in the fact that data is “noisy”: it comes with error. To see this a bit more, we can think about what would happen if we studied a setting where we know our true effect is zero. 

My fake study 

Imagine the following (fake) study. Participants are randomly assigned to eat a package of either blue or green M&Ms, and then they flip a (fair) coin and you see if it is heads. Your analysis will compare the number of heads that people flip after eating blue versus green M&Ms and report whether this is “statistically significant at the 5% level.”

To be clear: because this is a fair coin, there is no way that the color of the M&Ms eaten would influence how many heads you flip. So the “right” answer is that there is no relationship.

I used a computer program to simulate what would happen if we ran this study. I assumed we had 50 people in each group. First, I tried running the study one time. I calculated the share of heads in the blue and green groups and subtracted the share. This is my “treatment effect” — the impact of blue M&M eating relative to green on the share of heads. You can see the difference is very small. In this experiment the blue group threw 58% heads, and the green group 54%, for a slightly higher share of blue. 

In my fake study, the blue M&M group had a slightly higher chance of heads, but this difference is small. When I ran my statistical test, the difference was not statistically significant. Basically, I get nothing — I can’t rule out that the two groups are tossing heads at the same rate. 

However: we all know that when we flip a coin, or do anything else random, sometimes you get a string of heads — just by chance. Sometimes if you do 50 coin flips, 40 of them come up heads. It’s not likely! But it’s not impossible. And that fact means that, sometimes, even if there is no real relationship between M&M color and flipping heads, you can find one by accident.

After I did my study one time, with the results above, I did it 99 more times. In the end, I have 100 (computer-generated) versions of the same test. For each of them, I calculated the difference in the share of heads produced by the blue group versus the green group, and whether that difference was significant. The graph below shows the differences; the bars in yellow are differences I found that were significant. The dark-blue bar is the original result from my first experimental run.

That first bar — all the way to the left on your screen in yellow. In that version of my experiment, the blue M&M group were much less likely to flip heads than the green group were, and that result showed up as statistically significant even though it was definitely, definitely just by chance. 

In fact, out of the 100 times I ran this experiment, the data showed me 5 times where there appears to be a statistically significant relationship at the standard 5% level. This isn’t a mistake; it’s not something I messed up in doing it. This is, in fact, the definition of statistical significance at the 5% level. If you have a setting where the true impact of some treatment is zero, and you run it 100 times, you’ll expect to see a significant effect 5 of the 100 times. 

The real world 

How does this help us understand studies in the real world?

Now imagine someone says they have run a study to evaluate the impact of eating blue versus green M&Ms on performance on a test of multiplication speed. We know from the above example that even if there were no impact, if I ran this study 100 times we would expect to find a significant effect 5 of the 100 times.  

The researchers report an effect: green M&Ms make you multiply faster. There are two possible explanations for that finding. One is that there is actually an impact of M&M color on multiplication speed. The other is that this is a result that arises by chance — it’s one of the 5 in 100.  

If we were very sure that the researchers ran this study only one time, we could be pretty confident in the result — there is always the possibility that this is one of the “chance” significant findings, but the high level of significance gives us confidence. 

But: in the real world, we cannot be sure that we are seeing all the research that actually happened before publication. This leads to concerns about “publication bias” and “p-hacking,” which, in turn, makes us skeptical. More on these below, but for a simple explanation, try this cartoon

Publication bias and p-hacking

Publication bias and p-hacking are two shorthand, jargony ways to describe journal and researcher behaviors that make it more likely that the results we observe in published papers are occurring just by chance.

First: Academic journals are more likely to publish papers that find significant results. It’s not hard to see why this might be true. It’s not very interesting to publish a result saying that M&M color doesn’t impact multiplication speed — that’s kind of what we expected. But a result that says it does matter — that’s more surprising, and more likely to spark the interest of a journal editor.

This is what we call publication bias, and it turns out that this pattern means that the results we see in print are actually a lot more likely to be statistical accidents. Often, many researchers are looking into the same question. It’s not just my research team who is interested in the M&M-multiplication relationship — imagine there are 99 other teams doing the same thing. Even if there is no relationship, on average 5 of those teams will find something significant. 

These 5 “successful” teams are more likely to get their results published. That’s what we all see in journals, but what we do not see is the 95 times it didn’t work. When we read these studies, we’re assuming, implicitly, that we are seeing all the studies that were run. But we’re not, and we’re more likely to see the significant-by-chance results.

The issue of publication bias would be problematic just on its own. But it’s even more problematic when it interacts with researchers’ incentives. Researchers need to publish, and (see above) it is easier to do so when results are significant. This can lead to what people sometimes call p-hacking (the “p” stands for probability).

When researchers run a study, there are often a lot of ways to analyze the data. You can analyze the impact on different subgroups of the population. You can analyze the impact of different circumstances. You can test many different treatments. The idea of the xkcd cartoon is that you could test the impact of all the different M&M colors on some outcome. 

The more of these tests you do, the more likely you are to get a significant effect by chance. If you do 100 tests, you expect 5 of them to be significant at the 5% level. And then, because of publication bias, you write up the results focusing only on the significant groups or significant M&M colors. Of course, those are just accidental. But as a consumer of research, we do not see all the other things that happened in the background.

For these two reasons: some of what we see published, even if it is from a randomized experiment, is likely to be a result of statistical chance. There is a somewhat notorious paper that suggests that “most” research findings are false; I think this is overkill, but it’s a perspective. 

Is everything wrong?

Is all lost? Is all research garbage?

No, definitely not. Much research is great, and randomized trials are often compelling and convincing. How do we know which new studies are worth paying attention to? There is no simple answer here, but there are a couple of features that matter.

One very, very important issue is the number of people in the study, especially as it relates to the expected size of the impact. Before researchers run a study, they generally have an idea of the size of the effect they might get, based on what they know before from other information. For example, if I am studying the impact of M&M color on math performance, I would expect that effect to be very small (if it is there at all). On the other hand, if I’m studying the impact on math performance of keeping someone awake for 48 hours, I might expect that effect to be large. 

The larger the effect you expect, the smaller the sample of people you need to detect it statistically. This is called “statistical power,” and in well-designed experiments, researchers calculate this before they even start their study. They make an educated guess at the size of the impact, and they figure out how many people they need to detect that effect. 

When this doesn’t happen — when researchers do a small experiment on something where we expect the impact to be very small — we should not expect to learn anything from the data. The study is just not powered to detect the likely effects. If we do see an impact, it’s extremely likely that it is a statistical accident.

Shorthand here: large studies = better, especially when the expected effects are small. 

A second good feature to look for is confirmatory results. It should make us more confident if we see multiple experiments with the same results (commonly done in clinical drug trials). Or if we see one experiment that has a suggestive fact, and then a confirmatory experiment after that. More independent confirmation increases confidence. 

In practice, what this means is that the set of papers we should be paying attention to is a lot smaller than the set that gets media attention. 

A story about fish

I would like to end by talking about one of my very favorite academic papers ever.

To understand this story, you need to understand something about neuroscience. One thing people who study the brain like to do is put people into brain scan machines, called fMRI scanning. To somewhat oversimplify, these experiments show people different stimuli (pictures, words, etc.), and the researchers look at what parts of the brain light up. The idea is to figure out what parts of the brain do what. 

An issue with this method is that the brain has many places that can light up. These areas of brain tissue are called voxels, and there are about 130,000 of them. This fact has enormous potential for the problems I talked about above — in principle, you could be doing 130,000 different tests, looking at each voxel. With this approach you will get a lot of things that are significant at the 5% level.

In practice, researchers take approaches to try to mitigate this problem, but the people who wrote my favorite paper felt those approaches were definitely not sufficient to fix the problem. To show this, they did a study on a fish. A dead fish.  

Specifically, they studied a dead salmon. They put this dead salmon into an fMRI machine, and they gave it a task. As they write: “The salmon was shown a series of photographs depicting human individuals in social situations with a specified emotional valence, either socially inclusive or socially exclusive.” The study is careful. They provide a mirror to ensure the salmon can see the faces.

The authors then looked at what areas of the salmon’s brain lit up when the fish saw the photos, compared with a period of no photos. They found two areas of the brain that appeared significantly more electronically active during the photos. That is: if they had been doing a standard type of study, they would have reported that there were two areas of the brain that were responsive to emotionally charged photos. 

I want to mention again that, at the time, the salmon was dead. (Brains can have electrical activity postmortem.) In addition, salmon are not well known for being responsive to the facial emotions of people, even while alive. 

As the authors say, either they have discovered something amazing about the cognition of dead fish, or the methods that people are using in these fMRI studies are statistically problematic. They favor the latter explanation, and argue that these issues need to be addressed before we can really learn about the brain.

Thanks to Jesse Shapiro, Isaiah Andrews, and Lukasz Kowalik for helpful comments. All mistakes remain my own! 

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We are better writers than influencers, I promise. Thanks to our kids for filming our unboxing videos. People make this look way too easy. 

Only two weeks until our book “The Unexpected” is here! Preorder at the link in my bio. 💙

We are better writers than influencers, I promise. Thanks to our kids for filming our unboxing videos. People make this look way too easy.

Only two weeks until our book “The Unexpected” is here! Preorder at the link in my bio. 💙
...

Exciting news! We have new, high-quality data that says it’s safe to take Tylenol during pregnancy and there is no link between Tylenol exposure and neurodevelopmental issues in kids. Comment “Link” for a DM to an article exploring this groundbreaking study.

While doctors have long said Tylenol was safe, confusing studies, panic headlines, and even a lawsuit have continually stoked fears in parents. As a result, many pregnant women have chosen not to take it, even if it would help them.

This is why good data is so important! When we can trust the data, we can trust our choices. And this study shows there is no blame to be placed on pregnant women here. So if you have a migraine or fever, please take your Tylenol.

#tylenol #pregnancy #pregnancyhealth #pregnancytips #parentdata #emilyoster

Exciting news! We have new, high-quality data that says it’s safe to take Tylenol during pregnancy and there is no link between Tylenol exposure and neurodevelopmental issues in kids. Comment “Link” for a DM to an article exploring this groundbreaking study.

While doctors have long said Tylenol was safe, confusing studies, panic headlines, and even a lawsuit have continually stoked fears in parents. As a result, many pregnant women have chosen not to take it, even if it would help them.

This is why good data is so important! When we can trust the data, we can trust our choices. And this study shows there is no blame to be placed on pregnant women here. So if you have a migraine or fever, please take your Tylenol.

#tylenol #pregnancy #pregnancyhealth #pregnancytips #parentdata #emilyoster
...

How many words should kids say — and when? Comment “Link” for a DM to an article about language development!

For this graph, researchers used a standardized measure of vocabulary size. Parents were given a survey and checked off all the words and sentences they have heard their child say.

They found that the average child—the 50th percentile line—at 24 months has about 300 words. A child at the 10th percentile—near the bottom of the distribution—has only about 50 words. On the other end, a child at the 90th percentile has close to 600 words. One main takeaway from these graphs is the explosion of language after fourteen or sixteen months. 

What’s valuable about this data is it can give us something beyond a general guideline about when to consider early intervention, and also provide reassurance that there is a significant range in this distribution at all young ages. 

#cribsheet #emilyoster #parentdata #languagedevelopment #firstwords

How many words should kids say — and when? Comment “Link” for a DM to an article about language development!

For this graph, researchers used a standardized measure of vocabulary size. Parents were given a survey and checked off all the words and sentences they have heard their child say.

They found that the average child—the 50th percentile line—at 24 months has about 300 words. A child at the 10th percentile—near the bottom of the distribution—has only about 50 words. On the other end, a child at the 90th percentile has close to 600 words. One main takeaway from these graphs is the explosion of language after fourteen or sixteen months.

What’s valuable about this data is it can give us something beyond a general guideline about when to consider early intervention, and also provide reassurance that there is a significant range in this distribution at all young ages.

#cribsheet #emilyoster #parentdata #languagedevelopment #firstwords
...

I saw this and literally laughed out loud 😂 Thank you @adamgrant for sharing this gem! Someone let me know who originally created this masterpiece so I can give them the proper credit.

I saw this and literally laughed out loud 😂 Thank you @adamgrant for sharing this gem! Someone let me know who originally created this masterpiece so I can give them the proper credit. ...

Perimenopause comes with a whole host of symptoms, like brain fog, low sex drive, poor energy, and loss of muscle mass. These symptoms can be extremely bothersome and hard to treat. Could testosterone help? Comment “Link” for a DM to an article about the data on testosterone treatment for women in perimenopause.

#perimenopause #perimenopausehealth #womenshealth #hormoneimbalance #emilyoster #parentdata

Perimenopause comes with a whole host of symptoms, like brain fog, low sex drive, poor energy, and loss of muscle mass. These symptoms can be extremely bothersome and hard to treat. Could testosterone help? Comment “Link” for a DM to an article about the data on testosterone treatment for women in perimenopause.

#perimenopause #perimenopausehealth #womenshealth #hormoneimbalance #emilyoster #parentdata
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What age is best to start swim lessons? Comment “Link” for a DM to an article about water safety for children 💦

Summer is quickly approaching! You might be wondering if it’s the right time to have your kid start swim lessons. The AAP recommends starting between 1 and 4 years old. This is largely based on a randomized trial where young children were put into 8 or 12 weeks of swim lessons. They found that swimming ability and water safety reactions improve in both groups, and more so in the 12 weeks group.

Below this age range though, they are too young to actually learn how to swim. It’s fine to bring your baby into the pool (if you’re holding them) and they might like the water. But starting formal safety-oriented swim lessons before this age isn’t likely to be very helpful.

Most importantly, no matter how old your kid is or how good of a swimmer they are, adult supervision is always necessary!

#swimlessons #watersafety #kidsswimminglessons #poolsafety #emilyoster #parentdata

What age is best to start swim lessons? Comment “Link” for a DM to an article about water safety for children 💦

Summer is quickly approaching! You might be wondering if it’s the right time to have your kid start swim lessons. The AAP recommends starting between 1 and 4 years old. This is largely based on a randomized trial where young children were put into 8 or 12 weeks of swim lessons. They found that swimming ability and water safety reactions improve in both groups, and more so in the 12 weeks group.

Below this age range though, they are too young to actually learn how to swim. It’s fine to bring your baby into the pool (if you’re holding them) and they might like the water. But starting formal safety-oriented swim lessons before this age isn’t likely to be very helpful.

Most importantly, no matter how old your kid is or how good of a swimmer they are, adult supervision is always necessary!

#swimlessons #watersafety #kidsswimminglessons #poolsafety #emilyoster #parentdata
...

Can babies have salt? 🧂 While babies don’t need extra salt beyond what’s in breast milk or formula, the risks of salt toxicity from normal foods are minimal. There are concerns about higher blood pressure in the long term due to a higher salt diet in the first year, but the data on these is not super compelling and the differences are small.

Like with most things, moderation is key! Avoid very salty chips or olives or saltines with your infant. But if you’re doing baby-led weaning, it’s okay for them to share your lightly salted meals. Your baby does not need their own, unsalted, chicken if you’re making yourself a roast. Just skip the super salty stuff.

 #emilyoster #parentdata #childnutrition #babynutrition #foodforkids

Can babies have salt? 🧂 While babies don’t need extra salt beyond what’s in breast milk or formula, the risks of salt toxicity from normal foods are minimal. There are concerns about higher blood pressure in the long term due to a higher salt diet in the first year, but the data on these is not super compelling and the differences are small.

Like with most things, moderation is key! Avoid very salty chips or olives or saltines with your infant. But if you’re doing baby-led weaning, it’s okay for them to share your lightly salted meals. Your baby does not need their own, unsalted, chicken if you’re making yourself a roast. Just skip the super salty stuff.

#emilyoster #parentdata #childnutrition #babynutrition #foodforkids
...

Is sleep training bad? Comment “Link” for a DM to an article breaking down the data on sleep training 😴

Among parenting topics, sleep training is one of the most divisive. Ultimately, it’s important to know that studies looking at the short- and long-term effects of sleep training show no evidence of harm. The data actually shows it can improve infant sleep and lower parental depression.

Even so, while sleep training can be a great option, it will not be for everyone. Just as people can feel judged for sleep training, they can feel judged for not doing it. Engaging in any parenting behavior because it’s what’s expected of you is not a good idea. You have to do what works best for your family! If that’s sleep training, make a plan and implement it. If not, that’s okay too.

What’s your experience with sleep training? Did you feel judged for your decision to do (or not do) it?

#sleeptraining #newparents #babysleep #emilyoster #parentdata

Is sleep training bad? Comment “Link” for a DM to an article breaking down the data on sleep training 😴

Among parenting topics, sleep training is one of the most divisive. Ultimately, it’s important to know that studies looking at the short- and long-term effects of sleep training show no evidence of harm. The data actually shows it can improve infant sleep and lower parental depression.

Even so, while sleep training can be a great option, it will not be for everyone. Just as people can feel judged for sleep training, they can feel judged for not doing it. Engaging in any parenting behavior because it’s what’s expected of you is not a good idea. You have to do what works best for your family! If that’s sleep training, make a plan and implement it. If not, that’s okay too.

What’s your experience with sleep training? Did you feel judged for your decision to do (or not do) it?

#sleeptraining #newparents #babysleep #emilyoster #parentdata
...

Does your kid love to stall right before bedtime? 💤 Tell me more about their tactics in the comments below!

#funnytweets #bedtime #nightimeroutine #parentinghumor #parentingmemes

Does your kid love to stall right before bedtime? 💤 Tell me more about their tactics in the comments below!

#funnytweets #bedtime #nightimeroutine #parentinghumor #parentingmemes
...

Got a big decision to make? 🤔 Comment “Link” for a DM to read about my easy mantra for making hard choices. 

When we face a complicated problem in pregnancy or parenting, and don’t like either option A or B, we often wait around for a secret third option to reveal itself. This magical thinking, as appealing as it is, gets in the way. We need a way to remind ourselves that we need to make an active choice, even if it is hard. The mantra I use for this: “There is no secret option C.”

Having this realization, accepting it, reminding ourselves of it, can help us make the hard decisions and accurately weigh the risks and benefits of our choices.

#parentingquotes #decisionmaking #nosecretoptionc #parentingadvice #emilyoster #parentdata

Got a big decision to make? 🤔 Comment “Link” for a DM to read about my easy mantra for making hard choices.

When we face a complicated problem in pregnancy or parenting, and don’t like either option A or B, we often wait around for a secret third option to reveal itself. This magical thinking, as appealing as it is, gets in the way. We need a way to remind ourselves that we need to make an active choice, even if it is hard. The mantra I use for this: “There is no secret option C.”

Having this realization, accepting it, reminding ourselves of it, can help us make the hard decisions and accurately weigh the risks and benefits of our choices.

#parentingquotes #decisionmaking #nosecretoptionc #parentingadvice #emilyoster #parentdata
...

Excuse the language, but I have such strong feelings about this subject! Sometimes, it feels like there’s no winning as a mother. People pressure you to breastfeed and, in the same breath, shame you for doing it in public. Which is it?!

So yes, they’re being completely unreasonable. You should be able to feed your baby in peace. What are some responses you can give to someone who tells you to cover up? Share in the comments below ⬇️

#breastfeeding #breastfeedinginpublic #breastfeedingmom #motherhood #emilyoster

Excuse the language, but I have such strong feelings about this subject! Sometimes, it feels like there’s no winning as a mother. People pressure you to breastfeed and, in the same breath, shame you for doing it in public. Which is it?!

So yes, they’re being completely unreasonable. You should be able to feed your baby in peace. What are some responses you can give to someone who tells you to cover up? Share in the comments below ⬇️

#breastfeeding #breastfeedinginpublic #breastfeedingmom #motherhood #emilyoster
...

Potty training can feel like a Mount Everest-size challenge, and sadly, our evidence-based guidance is poor. So, I created a survey to collate advice and feedback on success from about 6,000 participants.

How long does potty training take? We found that there is a strong basic pattern here: the later you wait to start, the shorter time it takes to potty train. On average, people who start at under 18 months report it takes them about 12 weeks for their child to be fully trained (using the toilet consistently for both peeing and pooping). For those who start between 3 and 3.5, it’s more like nine days. Keep in mind that for all of these age groups, there is a range of length of time from a few days to over a year. Sometimes parents are told that if you do it right, it only takes a few days. While that is true for some people, it is definitely not the norm.

If you’re in the throes of potty training, hang in there! 

#emilyoster #parentdata #pottytraining #pottytrainingtips #toddlerlife

Potty training can feel like a Mount Everest-size challenge, and sadly, our evidence-based guidance is poor. So, I created a survey to collate advice and feedback on success from about 6,000 participants.

How long does potty training take? We found that there is a strong basic pattern here: the later you wait to start, the shorter time it takes to potty train. On average, people who start at under 18 months report it takes them about 12 weeks for their child to be fully trained (using the toilet consistently for both peeing and pooping). For those who start between 3 and 3.5, it’s more like nine days. Keep in mind that for all of these age groups, there is a range of length of time from a few days to over a year. Sometimes parents are told that if you do it right, it only takes a few days. While that is true for some people, it is definitely not the norm.

If you’re in the throes of potty training, hang in there!

#emilyoster #parentdata #pottytraining #pottytrainingtips #toddlerlife
...

For children or adults with severe food allergies, they can be incredibly scary and restrictive. We may imagine that it’s easy to deal with a peanut allergy by, say, not eating peanut butter sandwiches. But for someone with a severe version of this allergy, they may never be able to go to a restaurant, for fear of a severe reaction to something in the air. Right now, there’s only one approved treatment for severe allergies like this and it’s limited to peanuts.

This is why the new medication Xolair is very exciting. It promises a second possible treatment avenue and one that works for other allergens. A new trail analyzed data from 177 children with severe food allergies. Two-thirds of the treatment group were able to tolerate the specified endpoint, versus just 7% of the placebo group. This is a very large treatment effect, and the authors found similarly large impacts on other allergens. 

There are some caveats: This treatment won’t work for everyone. (One-third of participants did not respond to it.) Additionally, this treatment is an injection given every two to four weeks, indefinitely. This may make it less palatable to children. 

Overall, even with caveats, this is life-changing news for many families!

#xolair #foodallergies #allergies #peanutallergy #emilyoster #parentdata

For children or adults with severe food allergies, they can be incredibly scary and restrictive. We may imagine that it’s easy to deal with a peanut allergy by, say, not eating peanut butter sandwiches. But for someone with a severe version of this allergy, they may never be able to go to a restaurant, for fear of a severe reaction to something in the air. Right now, there’s only one approved treatment for severe allergies like this and it’s limited to peanuts.

This is why the new medication Xolair is very exciting. It promises a second possible treatment avenue and one that works for other allergens. A new trail analyzed data from 177 children with severe food allergies. Two-thirds of the treatment group were able to tolerate the specified endpoint, versus just 7% of the placebo group. This is a very large treatment effect, and the authors found similarly large impacts on other allergens.

There are some caveats: This treatment won’t work for everyone. (One-third of participants did not respond to it.) Additionally, this treatment is an injection given every two to four weeks, indefinitely. This may make it less palatable to children.

Overall, even with caveats, this is life-changing news for many families!

#xolair #foodallergies #allergies #peanutallergy #emilyoster #parentdata
...

If you have a fever during pregnancy, you should take Tylenol, both because it will make you feel better and because of concerns about fever in pregnancy (although these are also overstated).

The evidence that suggests risks to Tylenol focuses largely on more extensive exposure — say, taking it for more than 28 days during pregnancy. There is no credible evidence, even correlational, to suggest that taking it occasionally for a fever or headache would be an issue.

People take Tylenol for a reason. For many people, the choice may be between debilitating weekly migraines and regular Tylenol usage. The impacts studies suggest are very small. In making this decision, we should weigh the real, known benefit against the suggestion of this possible risk. Perhaps not everyone will come out at the same place on this, but it is crucial we give people the tools to make the choice for themselves.

#emilyoster #parentdata #tylenol #pregnancy #pregnancytips

If you have a fever during pregnancy, you should take Tylenol, both because it will make you feel better and because of concerns about fever in pregnancy (although these are also overstated).

The evidence that suggests risks to Tylenol focuses largely on more extensive exposure — say, taking it for more than 28 days during pregnancy. There is no credible evidence, even correlational, to suggest that taking it occasionally for a fever or headache would be an issue.

People take Tylenol for a reason. For many people, the choice may be between debilitating weekly migraines and regular Tylenol usage. The impacts studies suggest are very small. In making this decision, we should weigh the real, known benefit against the suggestion of this possible risk. Perhaps not everyone will come out at the same place on this, but it is crucial we give people the tools to make the choice for themselves.

#emilyoster #parentdata #tylenol #pregnancy #pregnancytips
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Parenting trends are like Cabbage Patch Kids: they’re usually only popular because a bunch of people are using them! Most of the time, these trends are not based on new scientific research, and even if they are, that new research doesn’t reflect all of what we’ve studied before.

In the future, before hopping onto the latest trend, check the data first. Unlike Cabbage Patch Kids, parenting trends can add a lot of unnecessary stress and challenges to your plate. What’s a recent trend that you’ve been wondering about?

#parentdata #emilyoster #parentingtips #parentingadvice #parentinghacks

Parenting trends are like Cabbage Patch Kids: they’re usually only popular because a bunch of people are using them! Most of the time, these trends are not based on new scientific research, and even if they are, that new research doesn’t reflect all of what we’ve studied before.

In the future, before hopping onto the latest trend, check the data first. Unlike Cabbage Patch Kids, parenting trends can add a lot of unnecessary stress and challenges to your plate. What’s a recent trend that you’ve been wondering about?

#parentdata #emilyoster #parentingtips #parentingadvice #parentinghacks
...

As of this week, 1 million copies of my books have been sold. This feels humbling and, frankly, unbelievable. I’m so thankful to those of you who’ve read and passed along your recommendations of the books.

When I wrote Expecting Better, I had no plan for all of this — I wrote that book because I felt compelled to write it, because it was the book I wanted to read. As I’ve come out with more books, and now ParentData, I am closer to seeing what I hope we can all create. That is: a world where everyone has access to reliable data, based on causal evidence, to make informed, confident decisions that work for their families.

I’m so grateful you’re all here as a part of this, and I want to thank you! If you’ve been waiting for the right moment to sign up for full access to ParentData, this is it. ⭐️ Comment “Link” for a DM with a discount code for 20% off of a new monthly or annual subscription to ParentData! 

Thank you again for being the best community of readers and internet-friends on the planet. I am so lucky to have you all here.

#parentdata #emilyoster #expectingbetter #cribsheet #familyfirm #parentingcommunity

As of this week, 1 million copies of my books have been sold. This feels humbling and, frankly, unbelievable. I’m so thankful to those of you who’ve read and passed along your recommendations of the books.

When I wrote Expecting Better, I had no plan for all of this — I wrote that book because I felt compelled to write it, because it was the book I wanted to read. As I’ve come out with more books, and now ParentData, I am closer to seeing what I hope we can all create. That is: a world where everyone has access to reliable data, based on causal evidence, to make informed, confident decisions that work for their families.

I’m so grateful you’re all here as a part of this, and I want to thank you! If you’ve been waiting for the right moment to sign up for full access to ParentData, this is it. ⭐️ Comment “Link” for a DM with a discount code for 20% off of a new monthly or annual subscription to ParentData!

Thank you again for being the best community of readers and internet-friends on the planet. I am so lucky to have you all here.

#parentdata #emilyoster #expectingbetter #cribsheet #familyfirm #parentingcommunity
...

Just eat your Cheerios and move on.

Just eat your Cheerios and move on. ...

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
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