Results of Flanagan et al. (2006) research synthesis
Flanagan et al. (2006) presented their conclusions in a single summary table (Table 2.14 of Flanagan et al., 2006). The broad Gc domain, and the narrow Gc abilities of language development (LD), lexical knowledge (VL), and listening ability (LS) were designated as related to both reading and math. The cognitive efficiency broad domains of Gs and Gsm were also implicated for reading and math, specifically the narrow abilities of perceptual speed (Gs-P), memory span (Gsm-MS), and working memory (Gsm- MW).   Gf, as well as the narrow abilities of induction (I) and general sequential reasoning (RG), are also listed as related to both reading and math (with a greater relevance for math noted). In reading, Flanagan et al. (2006) suggest that Gf is primarily related to reading comprehension and not basic reading skills. Finally, reading-specific broad and narrow ability relations listed by Flanagan et al. (2006) include Ga (“phonological awareness processing” or phonetic coding—PC) and Glr (“rapid automatic naming” or naming facility—NA; associative memory—MA). Gv was noted as not displaying any significant relations with reading and math achievement in the studies reviewed, although Flanagan et al. (2006) suggest that Gv abilities “may be important primarily for higher level or advanced mathematics (e.g., geometry, calculus)” (p. 45).
Although Flanagan et al. (2006) mention possible developmental (age)-related findings (e.g., Gc “abilities become increasingly more important with age”; phonetic coding and naming facility are “very important during the elementary school years”, p. 45), their developmental comments are general and lack specific age- differentiated information. Finally, Flanagan et al. (2006) mention possible non- CHC abilities that research suggests are related to school achievement. These include orthographic processing and morphological knowledge in reading.