Yesterday prof Wouter Duyck shared this review study by Gary Marks and Michael O’Connell and while I recognized a lot of the studies mentioned in the review, reading them all in one place gives a pretty damning view on a construct that is key in so many educational studies: SES or socio-economic status.

What are the takeaways from this review?

• The review provides overwhelming evidence that much of the current thinking about SES and student achievement is mistaken.
• The concept of SES is nebulous, difficult to measure, and only moderately associated with achievement.

The researchers, therefore, argue that focus should be on student performance ensuring that low achievers have rewarding educational and occupational careers and raising the overall skill levels of students.

And so this study becomes:

• Relevant
  Because the review shows with a lot of examples, but focusing for an important part on PISA-data, this:

SES measures are frequently based on proxy reports from students; these are generally unreliable, sometimes endogenous to student achievement, only low to moderately intercorrelated, and exhibit low comparability across countries and over time. There are many explanations for SES inequalities in education, none of which achieves consensus among research and policy communities. SES has only moderate effects on student achievement, and its effects are especially weak when considering prior achievement, an important and relevant predictor. SES effects are substantially reduced when considering parent ability, which is causally prior to family SES.

To give you a clear example:

Books in the home is even more problematic than parents’ education. Jerrim and Mickelwright (2014, p. 772) reported kappa statistics less than 0.2 between parents and their 15-year-old children’s reports on the number of books in the home, indicating only ‘slight’ agreement. They (2014, p. 774) also found that students who agree with parents’ estimates, score higher in PISA reading, with the extreme case of England, where children who agree with their parents’ estimate, score, on average, 0.35 standard deviations higher than those who disagree.

• Frustrating
  Because this means a lot of insights and results in research seems to be not that sure. Also, I learned *again* how difficult it is to compare different PISA rounds, while it’s being used by most policymakers base their arguments on exactly that. And as the authors write in their review, like most researchers in this field I do know the results on PISA for my region by heart.
• Dangerous
  This is the most important criticism I have against the review study. The authors seemingly suggest that looking at SES is not that important. This can be true if you regard SES as a nebulous concept, but at the same time, we do know that e.g. poverty can have an important effect on learning. The authors describe PISA and many other studies and researchers as too focussed on a blank slate view of education, in which e.g. heritability has no place. They are probably correct, but the answer can not be the opposite. There is pretty much always a strong continuous interaction between nature and nurture.  The researchers don’t want to state that the environment doesn’t play a role, but do read:

We are not arguing that the home environment is completely irrelevant to student performance. Very wealthy and high-income families can send their children to private schools, which increases the chances of university entry (Jerrim et al., 2016). Undesirable changes in home circumstances (e.g., job loss, divorce) can adversely impact student performance (Lehti et al., 2019; Nilsen et al., 2020). Parents influence their children in myriads of ways and most parents monitor their children’s education. However, the overall impact of the home environment, SES and parenting are much weaker than commonly assumed. The problem is that the SES model has become an idée fixe among researchers and policymakers, and they insist that it explains much of the variance in student achievement, is theoretically credible, and is sensitive to policies that aim to reduce educational inequalities.

Yesterday I was lucky to discuss this review with some fellow researchers IRL and we wondered if this study will have a huge effect on our thinking. The four of us agreed it should not as a final word but as a starting point, but guessed it won’t… Why? A lot of this has been known for quite a while, but it’s seldom being discussed and if it is being discussed things can get polarized very fast. Something that this review won’t solve neither, I think.