<p><p><p>The impact of date of birth on cognitive test scores is well documented across many countries, with the youngest children in each academic year performing more poorly, on average, than the older members of their cohort. However, relatively little is known about the driving forces behind these differences, at least in England; nor does there appear to have been a robust discussion regarding what, if anything, should be done in light of these disparities. We address both of these issues in this report.</p></p></p>