Prof Satoshi Araki and his PhD student Ms Miner Ye have published an article "Effectively maintained inequality in skill acquisition: Uncovering the heterogeneous effect of adult education on cognitive skills" in British Educational Research Journal, the flagship journal of the British Educational Research Association (https://doi.org/10.1002/berj.70297). In this paper, they examine the relationship between family background, cognitive skills, and adult education and training (AET) opportunities. Analysing data from the OECD Survey of Adult Skills (PIAAC) for Britain, the study shows that (1) AET is positively linked to adult cognitive skills; (2) on average, the association between AET and cognitive skills is stronger among disadvantaged individuals than the advantaged; but (3) the AET effect on top-level cognitive skills is larger among advantaged individuals. Based on these results, Prof Araki and Ms Ye argue that origin-based inequality in skill acquisition is effectively maintained in that the overall skill inequality seems weakening through AET, but the unequal distribution of most valuable skill segments rather intensifies. From a methodological viewpoint, they highlight the importance of examining effect heterogeneity of certain interventions or treatments across both social backgrounds and outcomes to better understand the equalising or stratifying nature of educational opportunities.