Researchers have found that fingers wrinkle in the same places every time due to the body’s response to water exposure. A study published in the Journal of the Mechanical Behavior of Biomedical Materials revealed that wrinkles follow the paths of blood vessels beneath the skin, which rarely change position. This consistency suggests that each person’s wrinkly pattern is unique and stable over time, similar to fingerprints. The findings challenge a long-held theory that wrinkling is caused by water absorption alone. Instead, prolonged soaking leads to nerve signals that trigger constriction of blood vessels, resulting in the familiar grooves.
Source: https://www.newser.com/story/369328/our-wet-fingers-prune-the-exact-same-way-each-time.html