The Disadvantages of Summer Babies


A new report from the Institute of Fiscal Studies in the U.K. examines the big difference that a few months can make in the student achievement of young children. Authors Claire Crawford, Lorraine Dearden and Ellen Greaves found (along with several previous studies, like this one and this one) that children born in summer months generally score lower on standardized tests and are seen as “underachievers;” while children born in September and autumn months are more academically and socially successful. From a press release about the study:

Previous research published by the Institute for Fiscal Studies (IFS) has shown that children born at the start of the academic year achieve better exam results, on average, than children born at the end of the academic year. In England, this means that children born in the autumn tend to outperform those born in the summer. New research published today by IFS, and funded by the Nuffield Foundation, shows that month of birth also matters for other characteristics and outcomes of young people growing up in England today.  

The idea that small age gaps can have big impacts is nothing new. In fact, it’s something we write about in Superfreakonomics, with the birthday breakdown of European soccer players: 43 percent of players were born in the first thee months of the year, while only 9 percent were born in the final three months. Children who are a few months older than their peers at 5 or 6 have more developed cognitive and motor skills, which makes them more advanced athletes and students. This early advantage can lead to self-fulfilling prophecies later on: the child thinks she is an underachiever, and so will often play that role.  

The IFS researchers found some other startling statistics: summer babies are between 20 and 30 percentage points (2.5 – 3.5 times) more likely to be considered below average by their teachers by age 7, and are 7 percentage points (2.5 times) more likely to report being always unhappy at school. They are also 6 percentage points (twice as likely) to report bullying, perhaps because of their smaller physical size.

Co-author Ellen Greaves states:  “…the government should be concerned about the wider educational experience of summer-born children, who appear to be at a disadvantage in terms of their well-being as well as their test scores.” 

[HT: duffmanbrown]

Joshua Northey

I love the work in this area because it helps demonstrate how striking the huge waste of human resources is on this planet.

Either due to socio-economic status, factors like this with enrollment, or tons of other inefficiencies we are absolutely terrible at fitting people into tasks that suit them well.

Surely the natural aptitude for playing soccer is distributed fairly randomly amongst the population, and yet we understand our HR processes so little that we end up with this type of distribution on the back end.

It is the same in many other disciplines and is a huge waste of the most valuable resource on earth, cognitive ability.

Thumb up 0 Thumb down 0


I guess the idiots who did this study forgot to take into consideration that children born in summer (unless they fail a grade) are ALWAYS the youngest children in their class. The cutoff for starting kindergarten is being 5 by the end of August in most states. My youngest son has an August birthday, but he is also an A-B student, mostly A's.


One local school mitigates this effect by shortening the age span of its classes for the first 3 years. Instead of having 3 classes each spanning an age range of 12 months, they have 4 classes each spanning a range of 9 months. With 3 terms per school year, children therefore move up a class every 2 terms rather than every 3. The school is very successful and massively over-subscribed, though I couldn't say whether it's for that reason.

Other schools show no sign of copying the idea, though. It shouldn't be too hard, since most of the schools near here have 2 or 3 classes per year group, each of which spans the entire year. Presumably it would be possible to have 2 classes each spanning 6 months or 3 classes each spanning 4 months and leave children in those groups for the first few years, with the aim of getting all groups to the same point by age 7 (what we call Key Stage 1 in the UK).

I wonder if it's been tried? And would it even help, or would it make the problem worse as the younger group suffers the tyranny of low expectations?

[WORDPRESS HASHCASH] The poster sent us '0 which is not a hashcash value.



Malcolm Gladwell covered this a while ago in Outliers - NHL players' birthdays are disproportionately in the first three months of the year. @Natasha, of course parenting plays a huge role in school performance. I personally am a summer baby, managed to score in the 98 percentile on the SAT, graduate with honors from an Ivy League school and go on to a successful career despite my "disadvantage". It just goes to show how frightening it is that we as a society are wasting so much talent. Certainly there are plenty of Summer (and Fall, and Winter and Spring) babies who aren't as lucky as I was or your daughter is to have parents in a position to offer so much guidance.

[WORDPRESS HASHCASH] The poster sent us '0 which is not a hashcash value.


Did they correct for income? In the US at least, there are statistically significant differences in the income of the parents of children born in each month. The reasons behind this aren't really understood, but 'prom babies' and poorer people trying to keep warm in the winter are some theories. Income could account for all of this.


Just a random comment that may spark some dialogue. Many teachers plan to have their children during the summer so as not to interfere with the school year. My husband is a teacher and we targeted late spring/summer birth dates for our two most recent children (one still in womb). Does this mean our educators are setting their own children up for failure in the system they are the biggest advocates of? I'd be interested in seeing data on that.

JSB does the current FMLA in the US factor into these choices people make (or try to make) is interesting data point. US is far, far behind in terms of parental leave - archaic really. What the potential downstream affect could be to children AND parents if gievn more appropriate leave (similar to other G7/G30/etc nations...)?? Years before 5 last the rest of their lives.


The sports advantage is that kids who are bigger and more coordinated are better than their younger peers, hence get more play time. By the time a few months makes no difference, they've had a lot more play/practice time.

Since most kids going to school get the same amount of teaching, regardless of success, you'd expect the advantage of being a few months older to fade over time. Is it still noticeable at age 10?

In England, most kids start formal education with school work at age 4 (reception year), when 6 months is a big difference. Comparing with American kids and with Russian kids (who usually start at age 7), would be interesting, as it would point out to what extent the difference in 7 year olds is a result of the age difference at 7 and to what extent it is a carry-over from the age difference at 4 or 5.