Digit ratio and academic performance in dentistry students

Abstract It has been suggested that prenatal testosterone (PT) is positively related to intelligence or learning-ability skills. Digit ratio (2D:4D) is a negative correlate of PT. This study considered the correlations between 2D:4D and success in practical and theoretical examinations in the Dental School curriculum of a Brazilian University. Overall, 80 subjects (40 males) had their right hand palm photographed by a digital camera attached to a standardising device. The index and ring fingers were measured using Adobe Photoshop. Digit ratio was correlated to the grades obtained by the students through four semesters. Theoretical and practical grades were significantly negatively correlated to digit ratio in males (and this was particularly so after the influence of age and hours of study were removed, p  = 0.02 and 0.004, respectively), but not in females ( p  = 0.89 and 0.77, respectively). This finding supports a link between high PT and intelligence in males. Our finding of no relationship between 2D:4D and examination marks in female students, suggests that PT may not influence intelligence in females.