Against kindergarten?

A new study on the mental health effects of kindergarten enrollment ages found strong evidence that a one-year delay dramatically improves a child’s self-regulation abilities even into later childhood.

According to the study co-authored by Stanford Graduate School of Education Professor Thomas Dee, children who started kindergarten a year later showed significantly lower levels of inattention and hyperactivity, which are jointly considered a key indicator of self regulation. The beneficial result was found to persist even at age 11.

“We found that delaying kindergarten for one year reduced inattention and hyperactivity by 73 percent for an average child at age 11,” Dee said, “and it virtually eliminated the probability that an average child at that age would have an ‘abnormal,’ or higher-than-normal rating for the inattentive-hyperactive behavioral measure.”

The study, aptly titled, “The Gift of Time? School Starting Age and Mental Health,” was published Oct. 5, by the National Bureau of Economic Research. A version of the article is also available here as a working paper from the Stanford Center for Education Policy Analysis at the GSE.

I have not yet read the study, but it seems to me this paper, along with some other recent results, does not exactly help the case for preschool…

For the pointer I thank Peter Metrinko.


So kicking the birds out of the nest a year early correlates to bad outcomes? Surprise, surprise! Let the policy recommendations flow.

Why would this be a surprise? Is there any evidence that attendance at a US District Public School is positively correlated with self-regulation abilities?

Maybe there is a negative causation and if you had kids skip public school altogether (rather than just delaying) they'd be even better off?

I guess the question is, why would this effect just be limited to Kindergarten? Maybe it'd be better to just delay school entry until they're a teenager or adult and send the kids straight to college? Studies seem to show that route results in "higher ACT scores, grade point averages and graduation rates compared with other college students".

The upper middle class is now delaying school arttendance for a year to get a better chance to get into a good college

Especially for boys, yep.

I thought that was more about sports.

One of many benefits. Bigger kid = better for sports, but also another year to mature, learn to sit still, etc.

Perhaps some are. But also, the 1st grade curriculum of 20 years ago is now the K curric. of today. Educators and people aware of this, sometimes ask themselves if they or the students they serve are ready for literacy a year earlier than the last generation. Because of this change, there is a heightened level of frustration among children leading to bad classroom behavior. Well-meaning pressure to educate all children at the highest level, with the highest expectations led to this change, but it is poorly conceived because early reading does not correlate to better later outcomes. Instead, it leads to frustration. Teachers and parents of immature (academically) kids often hold them back to make them ready for the curriculum. Please reconsider your oversimplified vantage.

Reverse causality - parents with kids who are a nightmare to deal with send them to school for the respite, parents with kids who are easy to deal with and/or low maintenance are more willing to keep them at home.

Also, parents who need free child care have to send them to school early, parents who don't need free child care may be more willing to keep them at home.

(I thought the upper middle class were keeping them longer in kindergarten rather than start them late?)

If you read some of the study you will see that the study design avoids these issues; besides 95% of the children likely were in preschool prior to Kindergarten.

Interesting. Our kids did not go to public school kindetgarten because it was only a half day. They were already in a full day private Montessori program where we kept them thru the kindergarten year. Any chance this dynamic is at play in the results?

>besides 95% of the children likely were in preschool prior to Kindergarten.

Wait, what's the reason why delaying Kindergarten helps, then, if they're already in a form of schooling before Kindergarten? How is exposing kids to Kindergarten different from pre-school?

How is exposing kids to Kindergarten different from pre-school?

I don't know how preschools break down between being just fun stuff and having more academic goals, but I know there are a lot of the former.

I seriously doubt the "study design" neutralizes confounds.

It actually does. They basically only compare kids born the day after vs. the day before they'd typically be able enter school, regardless of actual registration. This is highly correlated with delayed registration, exact birthdate is very tough for a parent to manipulate (and would require 6 years of foresight) and is almost definitely not correlated with other outcomes - unless you believe in astrology, I guess.

The evidence on preschool effectiveness, when to start Kindergarten, etc. seems mixed, to say the least. Before the FDA will approve drugs for sale in this country, they must pass randomized control trials (RCTs) for effectiveness (not just safety). It seems like the least we can do for poor kids is to give them the same protections for preschool treatment that the wealthy get for drugs. Until RCTs show a preschool program to be effective, the government should not encourage children to be subjected to them through subsidies, mandates, etc.

On the Kindergarten issue, again, there seems to be very mixed and hazy evidence, as is the case with many other educational policy questions. Given all the uncertainties, centralized educational policies that force a particular solution on all kids doesn't really make sense. Instead, using school choice vouchers so that parents, teachers, and schools can make use of localized preferences and knowledge makes more sense. At some point, if/when we get conclusive evidence about the optimal educational policies, then it might make sense to go back to the centralized, one-size-fits-all policies upon which our current public education system is based.

"we can do for poor kids is to give them the same protections for preschool treatment that the wealthy get for drugs"

The wealthy get drugs that go through a different approval process? Never heard that before. Not to mention that this didn't have anything to do with poor kids specifically.

Suppose one believes the following propositions simultaneously: (1) The wealthy have more access to medication and health care than the poor. (2) The FDA approval process is a net benefit, rather than hindrance, to patients because RCTs protect patients from ineffective treatments. (3) Universal preschool will help more poor kids get access to preschool. Then, requiring RCTs for drugs while not requiring them for universal preschool programs indeed disproportionately protects the wealthy over poor kids. (In fact, the same statement is true for any welfare program that has not been RCT-tested for effectiveness.)

Thus, if someone simultaneously supports universal preschool and opposes loosening regulations for drugs, then either they believe that government should favor the wealthy over poor kids or they must explain which of the three propositions they don't believe.

Just spitballing here, but it could be that said person recognizes that social sciences measuring educational effectiveness aren't as precise as medical sciences measuring pharmaceutical effectiveness, and that to expect the same rigor from each is foolhardy.

That is an argument against social sciences more than against RCTs.

Also an argument for "spitballing" policy itself.

I would characterize it as an argument for recognizing the limitations of social sciences and accepting that policy will simply always have to be developed with imperfect information, but YMMV.

Sadly the do-gooders at my Synagogue, who love to have the Government confiscate income and wealth to the productive class and give it to the non-productive class, are all about lobbying California State for "Universal Pre-school." One large conflict of interest: Most of the old-biddies on our "Universal Pre-K Action Committee" are school teachers.

I looked at it enough to observe the following:
----children who start relatively later due to their birthdays will be older children in the class. I can't find what about the study shows that the effect is not due to the later starters just being older than their classmate.

----the findings would only apply to the kindergarten environment that these students experienced; a preschool environment would likely be much different; in fact may expose the children to the type of play that the authors fear a child might lose by an early start to Kindergarten.

Verbatim from the study:
"Before they begin formal schooling, most children in Denmark (i.e., over 95 percent) are in daycare that is publicly provided and organized at the municipal level. Child care consists of center-based nurseries and family day care for children aged 1 to 3 years and daycare for children aged 3 to 6. ."

So the children who do better in the psychological tests may have more exposure to pre-school.!!

It would be useful to read the study and understand it before jumping to conclusions about what it says about preschool.

No need to get snarky about a study behind a paywall, but agree that the study appears to support the importance of a time for play-based preschool. I could only find an ungated working copy:

"The evidence for these effects is robust and, critically, persists in the latest wave of the DNBC when the children were aged 11. However, we also find that these mental-health gains are narrowly confined to one particular construct: the inattention/hyperactivity score (i.e., a measure indicating a lack of self regulation). Interestingly, this finding is consistent with one prominent theory of why delayed school starts are beneficial. Specifically, a literature in developmental psychology emphasizes the importance of pretend play in the development of children’s emotional and intellectual self-regulation. Children who delay their school staring age may have an extended (and appropriately timed) exposure to such playful environments."

My kindergarten was about play, for my children it was about getting a just start on math and writing.

If pre-school is about play and not education, then why should we want a government solution?

1) You can play at home. (and in fact it may be this rather than play that matters.)
2) You can play at private pre-school, the YMCA, or any childcare facility.

If you demand a government funded solution then vouchers would work the best, and remove the need for expensive government teachers and removes the suspicion that its really about jobs for teachers and union dues flowing to the politicians. You don't need teachers to watch kids do unstructured play. In fact, you may want to use non-teachers to make sure no teaching creeps in at all!

Rather than "not exactly help the case for preschool", I'd read this as rather "early education is in need of some rethinking". The idea that there is no set of experiences that could help a child is ludicrous. The question is what experiences those children have in their year off of school that helps them succeed later, and how you can scale up those experiences to benefit from economics of scale.

If the best experiences arrise through spontaneous order, then perhaps they "scale" automatically.

If they arise from an extended experience with the children's own parents, scaling would be nearly impossible.

I need a primer of when the U.S. can look to Denmark and when it cannot. Its getting confusing.

Do you support something? Look to Denmark.

Do you oppose something? Don't look.

Brilliant comment, thanks.

You have won the comments section

Yeah, I think results like this basically kills the pre-K excitement dead. And I'm saying this as a liberal who was kind of excited about pre-K. NOTHING EVER FUCKING WORKS.

Except the article is about kindergarten; almost all children in Denmark go to pre-K. Furthermore it just proves it is best to be one of the oldest in your Kindergarten class or spent more time in Pre-K before moving up.

A question without agenda: does anyone know what Dutch pre-K curriculum is like compared to Dutch kindergarten curriculum?

All the working paper says is that "the attributes of this daycare are centrally defined," although the amount of time spent in day care varies, presumably because parents drop-them-off or pick them up at convenience. The study claims its findings support the importance of play, so I suspect the daycare curriculum is probably not at all intensive.

Kindergarten has a specialized curriculum that covers "topics such as verbal and non-verbal communication, as well as science and nature." A minimum of three teaching hours a day. Suggestion of 200-day school year, which would be ten percent longer than most in the U.S.

Read the section on treatment heterogeneity: " Our remaining results indicate that the mental-health benefits of a higher school starting age are almost exclusively concentrated among socioeconomically advantaged children (i.e., higher parental education, income and birthweight). These results are consistent with the hypothesis that an earlier start to formal schooling confers comparative benefits to disadvantaged children."

I am not sure how the study defines Kindergarten. Kindergarten, in the USA, has become a highly regimented day of pre-reading, pre-numeracy drills, in the fall; followed on by highly regimented reading and numeracy drills in the afternoon. There is little play, little recess, little fine arts, no naps. Just drill and kill. It is an oppressive stultifying environment. It should surprise no one that US kindergarten has a long term adverse effect on its victims.

You must have quite the imagination. Have you conducted a thorough study of the elementary schools of all municipalities in the country? P.S. 5-6 year olds do not need naps.

Have you conducted a thorough study of all the 5-6 year olds in all the municipalities in the country?

Lol. Thanks for that comment, it was delicious.

My understanding of this study is that children who are older in their grade cohort do better academically than children who are younger. A similar result was found in soccer. Professional soccer players tended to be older in their grade cohort than the average. If the first sentence is correct, then the inference that people make about the lack of value of pre-school and kindergarten is incorrect. It does not say that starting young is without value, After all, one suspects that starting sports or learning a foreign language when you are young is preferred to starting when you are a teenager, if everyone started school at first grade, everyone would be older but their relative differences in their ages would be less. So the older children would on average not be at such an advantage and the younger would not be at such a disadvantage, but all would have missed the year of school. Of course, much of the analysis depends on what the children would have been learning if they were not in K-12, but in preschool, with their parents, etc.

It's not about academics but about hyperactivity, so I am not sure what the mechanism would be that makes a 6 year old in 1st grade is so much more hyperactive than a 6 year old in Kindergarten unless school is actually bad for them

Alternatively, the kids are getting one more year of pre-school play. Is pre-school required for the type of play needed? Or is pre-school the option necessitated by two-income households (or one parent households)?

The best insight I think I got from reading Judith Rich Harris was that the problem with any kind of fixed regime is that it will work with some kids but be actively harmful to the development of other children. So any change to an education regime (within the normal bounds) will work out to be statistically neutral. As an example your kid may thrive in a highly disciplined environment while my kid may be stifled and play up. If we changed to a more undisciplined school, my son may be a self starter which allows him to focus on his interests, while yours may be confused and lack direction. Same with early years schooling, probably works great for some kids, terrible for others. Perhaps the best approach is to leave parents to make decisions on this themselves, worse case it will be neutral, best case is that actually might pay attention to the feedback from their kids an adjust their environment to be more effective.

"The evidence for these effects is robust and, critically, persists in the latest wave of the DNBC when the children were aged 11. How-
ever, we also find that these mental-health gains are narrowly confined to one particular construct: the inattention hyperactivity score". Is that enough to say "against kindergarten" ???.... hmmmm (1) artifact of measurement (?) (2) Also the p-values didnt seem that low, so Bonferroni correction would probably wipe out all of the statistically significant results in this paper (?)

Hyperactivity in children at school is mostly a boy problem. Indeed, the "crisis" in education is mostly a (hyperactive and inattentive) boy problem. Being inside and sitting still and listening to a teacher for hours is not something boys do very well. Sure, it's not well-suited for many girls either, but for boys, it's torture. This study may not reveal so much about the adverse effects of kindergarten as the adverse effects of the conventional method for teaching children, in particular, boys. Here's an interesting fact: almost 90% of primary school teachers in the U.S. are female.

And who sets what time should be given to recess, physical education and fitness? Certainly not the teachers in the classroom. It's the managers ... and they are more likely to be men.

how about this: "it depends on the kid."

i bet a lot of kids have trouble with focus and attention that they would grow out of just fine if not nagged and therapized and delaying is the best thing to do.

"We found that delaying kindergarten for one year reduced inattention and hyperactivity by 73 percent for an average child at age 11,” - study
"I have not yet read the study, but it seems to me this paper, along with some other recent results, does not exactly help the case for preschool…" - tyler

I think Tyler is reading this entirely wrong. If the study shows anything, it is the benefits to kids of an additional year of pre-K.

Not pre-k in the way they want to run it, as an early academic environment

I am unsure about these studies, and so am tugged this way and that on policy. Seems to me though that if pre-k and k should be more like good daycare, less like school, and optional, RCTs are the way to find out.

Compared with what? Are the kids who aren't in kindergarten at home or are they in a full-time daycare? The former obviously isn't an option for many parents.

Ha ha, stupid parents! We force children to sit in a box all day, learning nothing more interesting than the alphabet, and then when they get restless and bored, we say it's a problem with them, not us.

I'm not sure that kindergarten is best when delayed, but I'm pretty sure it could be pedagogically improved to account for the fact that kids like to run around and have fun.

On the contrary, this appears to support keeping your children in kindergarten an extra year before starting first grade.


Uh, Denmark.
The measure of mental health is "relying on linked Danish survey and register data that include several distinct, widely used, and validated measures of mental health that are reported out-of-school among similarly aged children.

Read this article ( for some possible insight to what the costs and alternatives are for parents and of children below the age of 6 in Denmark. Then contrast this to the US model.


A better study to look at (cough, Tyler) if you have time is ( which finds disparate effects of early childhood between Denmark and the US. Where beneficial effects in the US erode but remain in Denmark. Perhaps a strong social safety net with income and social support makes a big difference.

Child Care and School Performance in Denmark and the United States
Gosta Esping-Andersen, Irwin Garfinkel, Wen-Jui Han, Katherine Magnuson, Sander Wagner, and Jane Waldfogel


Child care and early education policies may not only raise average achievement but may also be of special benefit for less advantaged children, in particular if programs are high quality. We test whether high quality child care is equalizing using rich longitudinal data from two comparison countries, Denmark and the United States. In Denmark, we find that enrollment in high-quality formal care at age 3 is associated with higher cognitive scores at age 11. Moreover, the findings suggest stronger effects for the lowest-income children and for children at the bottom of the test score distribution. In the US case, results are different. We find that enrollment in school or center based care is associated with higher cognitive scores at school entry, but the beneficial effects erode by age 11, particularly for disadvantaged children. Thus, the US results do not point to larger and more lasting effects for disadvantaged children. This may be because low income children attend poorer quality care and subsequently attend lower quality schools..

The study is week at best. There is a consistent pattern in research in this area. Large RCT's find no effect smaller studies with weaker design claim to find effects. Underneath all of this the effect of shared environment in twin and adoption studies (in the UK, Scandanavia, Australia, the US) suggest that there is a very low ceiling to improve anything with these methods.

A little research into Danish schools:

1. Shorter, more intense school day. Until recently, children attend primary school from 8AM to noon or 1PM. Students claim to like the longer schedule because of breaks. After school, young kids go to childcare facilities where they can play or do homework. Danish changed the short-day when they looked around at other OECD practices.

2. Longest school year among OECD countries. 42 weeks.

3. Classes stay together with the same teacher through early secondary education.

These all seem like educational approaches that do not have ADHD type of concerns as paramount.

Thanks PD Shaw. Do you know if any schools in the US do #3?

Children should begin schooling after (1) gaining independence and confidence by choosing to end co-sleeping, and (2) be appropriately disciplined. The age range depends upon the child, but it is usually between 5 and 7 years old. Some children takes longer to fully develop the necessary states.

Autonomy is shown to be important to self control.

Kindergarten like most institutions might reduce autonomy.

it is also possible that the ways kids learn to self regulate are idiosyncratic. And this is amply destructed in kindergarten.

Walter Michel studies show young kids trick themselves into self control. By covering their eyes, singing a song, talking to themselves etc.
All those tricks would be blocked in many kindergartens ..............

Am i missing something.

I don't understand... I read it as delay for maturity is good. (only about age)
Nothing to do with eliminating Kindergarten or pre-school

Agreed. The issue is that being relatively far along developmentally with respect to your peers means that you master what you are studying better, and this in turn helps you cope better overall for the duration of your education. Being a top student in your class from a relative perspective produces enduring gains. The studies cited by Malcolm Gladwell in Outliers regarding the birthdays of top athletes in relation to eligibility cutoff dates for various sports has captured a similar notion.

I'm glad I longer have to blame myself for my severe lack of self control.

I don't think it stops with 'hyperactivity' alone. In many cases, the same leads to under performance in academics. In India, we conducted a study across 600,000 students taking public exams at age 15-16. We found that the oldest kids (by about 7-9 mo) in class, on an average performed better than the rest by 10-12%.

May be more reasons, for delaying formal education, till the kids reach the required mental maturity.

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