If a Tendon Raises Up When You Touch Your Pinky to Your Thumb, Here’s What It Could Mean

Curious about evolution? A simple test can reveal a connection to our ancient ancestors. Place your forearm on a table, palm up, then touch your pinky to your thumb and lift your hand slightly. If you see a raised tendon in the middle of your wrist, that’s the palmaris longus—an ancient muscle once crucial for primates swinging through trees.

Nearly 10-15% of people lack this tendon, showing evolutionary change in action. While most retain this vestigial trait, those without it may represent ongoing human adaptation. Even our smallest features can tell stories of our evolutionary past, reminding us of our ancestral roots and the ongoing journey of human evolution.