The purpose of this study was to determine the relation between reading and working memory (WM) in the context of 3 major theories: the domain-specificity theory (debate) of WM, the intrinsic cognitive load theory, and the dual process theory. A meta-analysis of 197 studies with 2026 effect sizes found a significant moderate correlation between reading and WM, r = .29, 95% CI [.27, .31]. Moderation analyses indicated that after controlling for publication type, bilingual status, domains of WM, and grade level, the relation between WM and reading was not affected by types of reading. The effects of WM domains were associated with grade level: before 4th grade, different domains of WM were related to reading to a similar degree, whereas verbal WM showed the strongest relations with reading at or beyond 4th grade. Further, the effect of WM on reading comprehension was partialed out when decoding and vocabulary were controlled for. Taken together, the findings are generally compatible with aspects of the domain-specificity theory of WM and the dual process theory, but, importantly, add a developmental component that is not currently reflected in models of the relation between reading and WM. The findings suggest that the domain-general central executive of WM is implicated in early reading acquisition, and verbal WM is more strongly implicated in later reading performance as readers gain more experience with reading. The implications of these findings for reading instruction and WM training are also discussed. (PsycINFO Database Record

This study aimed to determine the relations between fluid intelligence (Gf) and reading/mathematics and possible moderators. A meta-analysis of 680 studies involving 793 independent samples and more than 370,000 participants found that Gf was moderately related to reading, r = .38, 95% CI [.36, .39], and mathematics, r = .41, 95% CI [.39, 44]. Synthesis on the longitudinal correlations showed that Gf and reading/mathematics predicted each other in the development even after controlling for initial performance. Moderation analyses revealed the following findings: (a) Gf showed stronger relations to mathematics than to reading, (b) within reading or mathematics, Gf showed stronger relations to complex skills than to foundational skills, (c) the relations between Gf and reading/mathematics increased with age, and (d) family social economic status (SES) mostly affected the relations between Gf and reading/mathematics in the early development stage. These findings, taken together, are partially in line with the investment theory but are more in line with the intrinsic cognitive load theory, mutualism theory, and the gene–SES interaction hypothesis of cognition and learning. More importantly, these findings imply an integration model of these theories from an educational and developmental perspective: Children may rely on Gf to learn reading and mathematics early on, when high family SES can boost the effects of Gf on reading/mathematics performance. As children receive more formal schooling and gain more learning experiences, their reading and mathematics improvement may promote their Gf development. During development, the negative effects of low family SES on the relations between Gf and reading/mathematics may be offset by education/learning experiences.