(Actual) Study of the Week: Academic Outcomes for Preemies

Now back to our regularly scheduled programming….

There’s a lurking danger in the “nature vs nurture” debate that has been so prominent in educational research for so long: people tend to assume that genetic influence means that something is immutable, while environmental influences are assumed to be changeable. The former is not correct, at least in the sense that there are a lot of genetically influenced traits that can be altered or ameliorated – all manner of physical skills, for example, are subject to the impact of exercise, even while we acknowledge that at the top of the distribution tiers, natural/genetic talents play a big role. Likewise, we can believe in educational efforts that somewhat ameliorate genetic influences even while we recognize that biological parentage powerfully shapes intellectual outcomes.

The obverse is even more often forgotten: just because an influence is environmental in nature, that does not mean we can necessarily change its effects. Lead exposure, for example, leads to relatively small but persistent damage to cognitive function. This is certainly environmental influence, but not one that we have tools to ameliorate. I’m not quite sure if we would call neonatal development “environmental,” but influences on children in the womb are a good example of non-genetic influences that are potentially immutable. And they are also another lens through which I want us to consider our tangled, frequently-contradictory intuitions about academic performance and just deserts.

Today’s Study, written by the exceptionally-Dutch-named Cornelieke Sandrine Hanan Aarnoudse-Moens, Nynke Weisglas-Kuperus,  Johannes Bernard van Goudoever, and Jaap Oosterlaan, is a meta-analysis of extant research on the academic outcomes of children who were born very prematurely and/or at very low birth weight. (For an overview of meta-analysis and effect size, please see this post.)

The studies had a number of restrictions in addition to typical quality checks. First, the studies consider had to look at very premature births, defined as less than 33 weeks gestation and/or with very low birth weight, defined as less than 1500 grams. Additionally, for inclusion in the meta-analysis, the studies had to track student performance to at least age 5, as this is where formal schooling begins and where responsible analysis of academic outcomes can be considered. These studies reported on academic outcomes, behavioral outcomes as represented by teacher and parent observation checklists/surveys, and so-called executive functioning variables, which includes things like impulse control and ability to plan (and which have been pretty trendy). All in all, data from 14 studies on academic outcomes, 9 on behavioral outcomes, and 6 on executive functioning were considered. (There was some overlap.) All in all, 4125 very preterm and/or very low birth weight children were compared to 3197 children born at term. The authors performed standard meta-analytic procedures involved pooling SDs and weighting by sample size and reported effect sizes in good old Cohen’s d. 

They also used a couple of statistical tests to attempt to adjust for publication bias. Publication bias is a troubling aspect of research studies that can undermine meta-analysis, particularly problematic given that meta-analysis is often viewed as a way to ameliorate (never eliminate) other problems like p-value hacking or similar. Publishing bias refers to the fact that journals are much more likely to publish studies with significant effects that those without them. This has several bad outcomes – for one, it provides perverse incentives for academics trying to get jobs and tenure. But it also distorts our view of reality. We adjust for the various issues with individual studies, in part, by looking at a broad swath of research literature. But if the non-significant results are sitting in a drawer while significant results are in Google Scholar, that’s not going to help, even with meta-analysis.

The results are not particularly surprising, but are sad all the same: children born very prematurely and/or at very low birth way have persistently worse academic outcomes compared to similar children. In terms of academic outcomes, we’re talking about -0.48 SD for reading, -0.60 SD for mathematics, and -0.76 for spelling. These are, in context of educational research, large effects. There was some variation between studies, as is to be expected in any meta-analysis, but this variation was not large enough to undermine our confidence in these results. Checks for publication bias came up largely clean as well. There are also findings indicating that children born premature have problems with attention, verbal fluency, and working memory. These effect sizes had no meaningful relationship to the age of assessment, suggesting that these problems are persistent. With a few exceptions, these relationships are continuous – that is, children with lower gestational ages and birth weight are generally worse off in terms of outcomes even when compared to other children born prematurely and/or at low birth weight.

First, this is very important to say: the studies included in this meta-analysis represent averages. We live in a world of variability. There are certainly many children who are born severely prematurely and go on to academic excellence. It would be wrong to assume that these influences indicate a certain academic destiny, as it is for any variable we examine in educational research. The trends, however, are clear. Sadly, other research suggests that these problems are likely to extend into at least young adulthood.

What are some of the consequences here? Well, to begin with, I think it’s another important facet of how we think about educational outcomes and how much of those outcomes lie outside of the hands of students, parents, and teachers. No one has chosen this outcome. For another thing, there’s the breaking of the nature/nurture binary I pointed out above. This is a non-genetic but uncontrolled introduction of major influence into the educational outcomes of children. I don’t mean to be fatalistic about things;  there’s always a chance that we’ll find some interventions that help to close these gaps. But I think this is another reason for us to get outside of a moralistic framework for education, where every below-average outcome has to be the fault of someone – the parents, the teachers, or the student themselves. 

And again, I think this points in the direction of a societal need to expand our definition of what it means to be a good student, and through that, what it means to be a valuable human being. True, very early births are comparatively rare, though almost 10% of all American births are preterm. (Like seemingly everything else in the United States, preterm birth rates are influenced by race, class, and geography.) But this dynamic is just another data point in a large set of evidence that suggests that academic outcomes are largely outside of the hands of individuals, parents, and teachers, particularly if we recognize that genetic influence is not controlled by those groups. What’s interesting with premature babies is that I doubt anyone would think that they somehow deserve worse life outcomes as a result of their academic struggles. Who could be so callous? And yet when it comes to genetic gifts – which are just as uncontrolled by individuals as being born prematurely – there are many who think it’s fine to disproportionately hand out reward. I don’t get that.

Ultimately, rather than continuing to engage in a quixotic policy agenda designed to give every child the exact same odds of being a Stanford-trained computer scientist, we should recognize as a society that we will always have a range of academic outcomes, that this means we will always have people who struggle as well as excel, and that to a large extent these outcomes are not controlled by individuals. Therefore we should build a robust social safety net to protect people who are not fortunate enough to be academically gifted, and we should critique the Cult of Smart, recognizing that there are all manner of ways to be valuable human beings.