Smaller fingers may create a more precise sense of touch, according to a study published this week in the Journal of Neuroscience. Anecdotally, researchers have observed that women tend to have a finer sense of touch than men, but until now it wasn’t very clear why. This new research suggests that it may just have to do with their generally tinier fingertips—smaller fingers are more sensitive because of a denser concentration of sensory receptors, they conclude.
Researchers recruited 100 university students and measured the size of their index fingers. They then asked participants to complete tests designed to measure sensitivity to touch—pushing their fingertips against surfaces that had a series of increasingly narrow grooves. They found that, regardless of gender, the smaller the fingertips, the finer the sense of touch.
Littler fingertips are likely more sensitive because of the distribution of sensory receptors—the less surface area to spread out across, the closer together the receptors are. While previous research has shown that this is the case for sensory receptors that pick up on vibration, this new study suggests that this may also be true for Merkel receptors, which read stationary, tactile information—such as the width of grooves pressed down upon by a finger. To measure the density of Merkel receptors, researchers analyzed placement of sweat pores on participants fingers, where Merkel receptors tend to cluster. What they found confirmed their suspicions—sweat pores (and Merkel receptors) were concentrated more densely among participants who had smaller (and more sensitive) fingertips.
