How to measure it

This is the protocol we followed in our most recent papers. You can find detailed information along this guide.

Participants are asked to place both their hands gently but firmly on a scanner to ensure correct scanning. In most cases, we can easily measure the ratio from the scanned pictures. It's important to use a high-resolution scanner allowing for large-scale images in Photoshop.

We measured the distance between the basal crease and the tip of the finger using Photoshop. Figure on the right provides an example and illustrates how finger lengths were measured.