Bethany Gower

2 months ago | onlinelibrary.wiley.com | Bethany Gower |Matthew Russell |Samantha J. Peterson |Jordan M. Tomkinson

1 Introduction The ratio of the lengths of the second (2D, the index finger) and fourth (4D, the ring finger) digits in humans is known as the digit ratio (2D:4D). The 2D:4D appears set by the end of the first trimester of pregnancy (Galis et al. 2010; Malas et al. 2006) and is stable throughout life (McIntyre et al. 2005; Trivers et al. 2006). Males generally have lower 2D:4Ds than females (Bernardino et al. 2025; Manning et al.