There is a new Best Evidence in Brief, and this time, I picked this very relevant study from this biweekly newsletter, this piece written By Winnie Tam, Centre for University and School Partnership, The Chinese University of Hong Kong.

A substantial body of research has established links between reading and mathematics skills, as well as between reading and writing. Given that these skills also share abilities such as executive function and higher-order cognition, it is reasonable to hypothesize a connection between mathematics and writing skills.

A meta-analysis by Kim and colleagues investigated the correlation between mathematics and writing skills by categorizing them into lower-order and higher-order subskills. In mathematics, skills involving information retrieval and an understanding of magnitude (e.g., arithmetic, calculation fluency) were considered foundational (or lower-order) skills, whereas skills involving reasoning and comprehension (e.g., word-problem solving, data interpretation) were higher-order skills. In writing, transcription skills (spelling and handwriting/keyboarding) were foundational, while written composition was a higher-order skill.

The meta-analysis included 211 studies with 564 effect sizes, primarily from English-speaking participants. Results showed that the  overall correlation between mathematics and writing skills was moderate (r = .48), with grade level significantly affecting this correlation. The effect was strongest among lower primary students (K-Grade 2: r = 0.52), decreased through upper elementary (Grade 3-6: r=0.42), and continued to decrease through college students’ and adults’ levels (r = 0.30).

Given the potential overlap between grade level and skill level, the analysis was further disaggregated by grade level and skill level. In primary grades, foundational writing and foundational mathematics skills were moderately correlated (r=0.59), while the correlation between higher-order writing and higher-order mathematics was +0.48. Among university learners, the foundational link was +0.36, and the higher-order link was +0.25.

These findings support a substantial correlation between mathematics and writing skills that decreases as grade level increases, with  the higher-order link being comparatively weaker. The authors speculated a twofold explanation: a plateau of foundational skills and the possibility that different cognitive skills might be involved in higher-order tasks, warranting further exploration.