Does handedness or digit ratio (2D:4D) predict lateralised cognitive ability?

► We calculated the ratio of the length of the index and ring fingers (2D:4D) on each hand. ► Right 2D:4D minus left 2D:4D (Dr-l) predicted scores on a test of phonological memory. ► Handedness predicted performance only if Dr-l was excluded from the predictor variables. ► Aspects of digit ratio predict cognitive performance.