• DOI:10.1017/S2040174420001294
• Corpus ID: 231664924

Digit ratio (2D:4D) and amniotic testosterone and estradiol: an attempted replication of Lutchmaya et al. (2004).

@article{Richards2021DigitR,
  title={Digit ratio (2D:4D) and amniotic testosterone and estradiol: an attempted replication of Lutchmaya et al. (2004).},
  author={Gareth Richards and Wendy V. Browne and Mihaela Constantinescu},
  journal={Journal of developmental origins of health and disease},
  year={2021},
  pages={
          1-6
        }
}

• G. Richards, Wendy V. Browne, M. Constantinescu
• Published 21 January 2021
• Psychology
• Journal of developmental origins of health and disease

The ratio of length between the second (index) and fourth (ring) fingers (digit ratio or 2D:4D) is frequently employed as a retrospective marker of prenatal sex hormone exposure. Lutchmaya et al. (2004) reported that the ratio of testosterone (T) to estradiol (E) present in second-trimester amniotic fluid was negatively correlated with digit ratios for the right hand (but not the left hand) in a sample of 29 children at 2-year follow-up. This observation is frequently cited as evidence for the measure's validity but has not been replicated. We therefore present the findings of another study of amniotic T and E that did not find evidence for these effects at 4½-year follow-up. The confidence intervals were large, the direction of correlations observed was generally erratic, and the overall findings question the premise that second-trimester sex hormones affect the development of digit length ratios in humans.