Have you ever wondered what makes someone a good athlete? A recent study at the University of North Dakota suggests that the length of your fingers may indicate athletic ability.
Grant Tomkinson, a professor in the kinesiology and public health education department at the University of North Dakota, worked with his son, Jordan Tomkinson, to publish a study that examined the ratio of the length between your pointer finger and ring finger, also known as the 2D:4D ratio.
Measured from the mid-point of the bottom crease, where the fingers join the hands, to the tip of the fingers, the 2D:4D ratio shows levels of prenatal hormones such as estrogen and testosterone. The study was published in the journal Early Human Development.
“There is some indirect evidence that this digit ratio of the length of the fingers, is determined during early fetal development by testosterone — the more testosterone the fetus produces, the longer the ring finger, so the smaller the digit ratio,” Tomkinson told ScienceDaily. “Testosterone is the natural steroid hormone that enhances sport, athletic and fitness test performance. In general, people with smaller digit ratios are better athletes.”
Previous studies have shown that the ratio is associated with spatial skills, handedness, cognitive abilities, academic performance and athletic ability. The ratios also differ between men and women as well as among ethnic groups, with Caucasian children having higher ratios than African American or Southeast Asian children.
Researchers have previously conducted studies on the effect of the 2D:4D ratio on the athleticism of grown men, finding that a lower ratio led to a better handgrip which led to better performance overall. However, the link between athletic ability and the ratio had yet to be explored in adolescent boys. In this study, Tomkinson and his son recruited 57 Caucasian adolescent boys to their study, controlling for both age and reported differences in varied ethnic groups.
Tomkinson and his son measured the 2D:4D ratio of boys aged 13 to 18 years old. They also measured the height, weight and body mass index (BMI) of each boy. To measure handgrips, indicative of muscle strength and therefore athletic ability, participants squeezed a Takei T.K.K. 5401 digital handgrip dynamometer, a device used for measuring torque. In rehabilitation settings, physical therapists typically use a handheld dynamometer, like the one used in this study, to evaluate a patient’s physical status.
Participants tightly gripped the dynamometer, held it above their heads and then squeezed as hard as they could while moving the device in an 180 degree arc.
Tomkinson and his son adjusted the strength of each patient’s grip for age and BMI.