A link between handedness and mathematical skills exists, but it is more complex than commonly believed, according to a study led by the University of Liverpool.
The association between handedness and mathematical ability has long been debated. Prior studies have produced mixed claims: some reported that left-handed people excel in mathematics, others suggested that strong right-handers perform worse, and more recent reports proposed that ambidextrous individuals might be at a disadvantage. This new study aims to clarify those conflicting findings by examining handedness as a continuous trait and by testing a large, diverse sample of school-age children and adolescents.
Researchers from the University of Liverpool and the University of Milan assessed approximately 2,300 students in Italy, aged 6 to 17, using a set of standardized mathematical tasks. Participants completed basic arithmetic exercises and more complex problem-solving tasks designed to measure different aspects of mathematical competence. To measure handedness, the team used the Edinburgh Handedness Inventory, a widely used questionnaire that quantifies the degree to which an individual favors the right or left hand across a variety of everyday activities. By treating handedness as a spectrum rather than a simple left/right label, the researchers were able to analyze how varying degrees of lateral preference relate to mathematical performance.
Giovanni Sala, a psychologist at the University of Liverpool and one of the study’s authors, reported a measurable relationship between handedness and mathematical skill. “We found a moderate but statistically significant correlation between handedness and mathematics performance,” Sala explained. “Handedness accounted for roughly 5–10% of the variance in mathematics scores — a relatively large effect for a single individual difference measure like handedness.” While this does not imply that handedness determines mathematical ability, the result suggests it is a meaningful factor among many that influence school math achievement.
Importantly, the study shows the handedness–mathematics relationship is nuanced and influenced by multiple factors. The effect varied by age, by the specific type of mathematical task, and by gender. For example, children who were highly lateralized — that is, strongly left- or right-handed — tended to perform below the sample average on some measures of math. This suggests that extreme lateralization may be linked with weaker math outcomes in younger children. However, the pattern changed in adolescence: male left-handers in the older age group performed notably better than their peers, indicating that developmental factors and gender can interact with handedness to influence mathematical skills.
These findings underscore that handedness is not a simple predictor of math talent or weakness. Rather, handedness appears to be one of several individual differences that together shape mathematical development. The 5–10% variance accounted for by handedness indicates it can be a meaningful contributor in educational and cognitive research, but it is far from the only determinant. Socioeconomic factors, quality of instruction, cognitive abilities such as working memory and spatial reasoning, and motivational elements also play major roles.
The authors emphasize caution in interpreting the results. “Our study should not be viewed as producing definitive answers about who will succeed in mathematics based on hand preference alone,” Sala noted. Instead, the research represents a step toward a more comprehensive model that can reconcile conflicting prior results by considering handedness as a graded characteristic and by examining interactions with age, task type, and gender.
Source: Sarah Stamoer – University of Liverpool
Image Source: The image is adapted from the University of Liverpool press release.
Original Research: The study was presented at the British Psychological Society meeting held in Nottingham, 26–28 April 2016.