Upload your hand.
A clear photo of your right palm, fingers spread. We measure your 2D:4D digit ratio — a prenatal androgen marker validated across a 2025 meta-analysis of 227,648 participants. Free. Three minutes. Personalized RATIO Report at the end.
The Branch · The Photo We Need

Right hand. Palm up. Fingers together and straight.
Shoot from directly above against a dark, plain surface. No rings, no watch. We measure from the base crease of your index (2D) and ring (4D) fingers to the tips, then divide 2D by 4D.
Not sure what you're looking at? In most men, the ring finger is subtly longer than the index. In most women, they're about the same. Your number is yours — not a verdict, a starting point.
