Laterality, hand control and scholastic performance: a British birth cohort study
- 1Psychiatric Research Centre, Örebro County Council, Örebro, Sweden
- 2Department of Clinical Neuroscience, Division of Psychiatry, Karolinska Institutet, Stockholm, Sweden
- 3Clinical Epidemiology and Biostatistics Unit, Örebro University Hospital, Örebro, Sweden
- 4Stress Research Institute, Stockholm University, Stockholm, Sweden
- 5School of Health and Medical Sciences, Örebro University, Örebro, Sweden
- 6Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden
- 7Department of Primary Care and Public Health, Charing Cross Hospital, Imperial College, London, UK
- Correspondence to Dr Tabita Björk;
- Received 18 August 2011
- Accepted 30 January 2012
- Published 22 March 2012
Objectives To use simple measures of laterality and hand control that can identify a greater risk of poorer scholastic ability, potentially signalling suboptimal hemispheric lateralisation.
Design Analysis of material from a birth cohort study.
Setting Members of the National Child Development Study, a British birth cohort study following people born in 1958.
Participants 10 612 children who undertook tests at age 11 years.
Primary outcome measures Teacher-administered tests of non-verbal general ability, verbal general ability, reading comprehension and mathematics.
Results Linear 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.
Conclusions Measures 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.
To cite: Björk T, Brus O, Osika W, et al. Laterality, hand control and scholastic performance: a British birth cohort study. BMJ Open 2012;2:e000314. doi:10.1136/bmjopen-2011-000314
Contributors Dr TB was involved in drafting the manuscript and developing the analytic strategy. Mr OB was responsible for conducting the statistical analysis and produced the tables. Dr WO provided input on aspects of neurodevelopment. Professor SM devised the hypothesis and study design and was involved in drafting the manuscript. All the authors contributed to critical revision of the manuscript.
Funding This study received funding from the Örebro County Council Research Committee, Sweden, and from Economic and Social Research Council grant RES 596-28-0001 to the International Centre for Life Course Studies.
Competing interests None.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement All data used for this research were from the National Child development Study, available through the UK Data Archive (http://www.data-archive.ac.uk/).
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