The ratio of the length of the second digit (index finger) divided by the fourth digit (ring finger) tends to be lower in men than in women. This 2D:4D digit ratio is often used as a proxy for prenatal androgen exposure in studies of human health and behavior. For example. 2D:4D ratio is lower (i. https://www.mariameetsanna.com/product-category/1-professional-hot-air-brush/