The Effect of Handedness on Mental Arithmetic: A Longitudinal Large-Scale Investigation Through Smart Mobile Devices

Abstract

The proposal has been made that a weak lateralization of the human brain may be associated with a developmental delay. We studied whether this hypothesis extends to the domain of simple and complex arithmetics when tasks are performed through an educational application for smart mobile devices. We comparatively analyzed through linear mixed-effects models the times of more than 3,500,000 responses to these types of problems performed by more than 15,000 right-handed, left-handed, and ambidextrous individuals who played through an application specifically designed to learn mental arithmetic. All of our results unanimously evidenced no differences in response times between left and right-handers and higher time values for nonlateralized users than lateralized individuals. Our results support the hypothesis tested and also show that these effects of time delay are accentuated with high levels of training and in more complex operations. We share the data for future research.