Gustavo Parisi’s scientific contributions

General Audience Summary Researchers have tried to understand the set of cognitive and noncognitive skills involved in mathematical ability because of both its primary need in multiple situations of daily life and its unavoidable requirement for successfully pursuing certain careers. Certain brain functions, such as manual control (handedness) or speech production, are known to be controlled or influenced more by one cerebral hemisphere than the other (hemispheric lateralization). This hemispheric specialization would provide an evolutionary advantage, while conversely a weak lateralization could be associated with a delay in development. In particular, although many studies have explored the link between mathematical ability and hand preference, the relation between these two traits remains highly controversial. Moreover, the statement has been made that since these effects are subtle, their detection requires large-scale samples. Consistent with the aforementioned context, we have analyzed the longitudinal performance of more than 15,000 right-handed, left-handed, and ambidextrous individuals in single-digit and multidigit sums and products performed through an application for smart mobile devices. All our results unanimously evidenced that no significant differences exist between left- and right-handers in the speed to solve the proposed arithmetic tasks. We could observe, however, that nonlateralized (ambidextrous) users took longer to solve the tasks than lateralized individuals, with all these behaviors being consistent with the aforementioned theoretical framework. The results also revealed that these differences in speed are accentuated in advanced stages of training and in more complex operations.