Handedness, Health and Cognitive Development: Evidence from Children in the NLSY

Using data from the child supplement of the US National Longitudinal Survey of Youth, and fitting three-level random-effects models of child health and cognitive development, we test whether left-handed children have different outcomes from those of their right-handed counterparts. The health measures cover both physical health and mental health, and the cog- nitive development test scores span vocabulary, mathematics, reading and comprehension. Overall we find little evidence to suggest that left-handed children have a significantly higher probability of experiencing injury, illness or behavioural problems. In contrast, we find that left- handed children have significantly lower cognitive development test scores than right-handed children for all areas of development with the exception of reading. Moreover, we find no strong evidence that the left-handedness effect differs by gender or age.