Laterality, hand control and scholastic performance: a British birth cohort study

Abstract

ObjectivesTo use simple measures of laterality and hand control that can identify a greater risk of poorer scholastic ability, potentially signalling suboptimal hemispheric lateralisation.DesignAnalysis of material from a birth cohort study.SettingMembers of the National Child Development Study, a British birth cohort study following people born in 1958.Participants10 612 children who undertook tests at age 11 years.Primary outcome measuresTeacher-administered tests of non-verbal general ability, verbal general ability, reading comprehension and mathematics.ResultsLinear regression produced associations (and 95% CIs) with tests of verbal general ability, non-verbal general ability, reading comprehension and mathematics scores for the lowest third (compared with highest) of a left-hand control test involving picking up matches of −1.21 (−1.73 to −0.68; p<0.001), −0.72 (−1.14 to −0.29; p=0.001), −0.70 (−1.06 to −0.35; p<0.001) and −1.32 (−1.90 to −0.73; p<0.001). Among those in the lowest third of the right-hand control test score, mixed-handedness compared with right-handedness was associated with poorer scholastic performance, with regression coefficients (and 95% CIs; p values) of 1.90 (−3.01 to −0.80; p=0.001), −1.25 (−2.15 to −0.35; p=0.007), −1.28 (2.04 to −0.53; p=0.001) and −1.33 (−2.53 to −0.13; p=0.030). The estimates are for a point change in the scholastic test scores, after adjustment for sex, left-hand motor function and social class. Statistically significant associations with mixed-handedness were only observed for the lowest third of right-hand motor function.ConclusionsMeasures involving poorer left-hand motor function may represent useful markers of reduced cognitive function possibly reflecting suboptimal hemispheric lateralisation. Crude measures of laterality such as reported non-right-handedness may be more useful for research when combined with measures of motor function.

Developmental Risk: Evidence from Large Nonright-Handed Samples

“…A more recent study [82] using a multiple regression approach, showed that the Mayringer and Wimmer's [81] reanalysis suffered from statistical problems and that the lower scores close to the point of equal hand skill reported by Crow et al [25] are part of a general monotonic relationship of laterality to cognitive ability, which is independent of overall hand skill. Additionally, our findings are in accordance with recent studies [83,84] which indicated that mixed handedness compared to right handedness was associated with poorer scholastic performance. Overall from the aforementioned studies [25,[82][83][84] we could conclude that mixed handedness could aid in the recognition of children who are at risk for academic problems.…”

“…Additionally, our findings are in accordance with recent studies [83,84] which indicated that mixed handedness compared to right handedness was associated with poorer scholastic performance. Overall from the aforementioned studies [25,[82][83][84] we could conclude that mixed handedness could aid in the recognition of children who are at risk for academic problems.…”

Exploring human brain lateralization with molecular genetics and genomics

“…Some studies have found that variability in lateralized brain structures, functions, or behaviors is weakly associated with cognitive or behavioral performance, including verbal ability and scholastic achievement . For example, Bjork et al . analyzed data on 10,612 children from a British birth cohort and observed an association between mixed‐handedness and slightly reduced performance on school tests, including tests of verbal ability and mathematics.…”

Laterality of handgrip strength: age‐ and physical training–related changes in Lithuanian schoolchildren and conscripts

“…On the other hand, left‐handed individuals are often talented, more likely to have higher IQs, may have greater intermanual coordination, smaller asymmetries in hand skills, and less lateralization in language dominance than right‐handers . Recently, mixed‐handedness (not left‐handedness) was related to poorer mental abilities …”