Overall, our findings challenge the view that the 2D:4D ratio provides a reliable marker of prenatal androgen exposure underlying variation in sexual orientation and question assertions that publication bias in this literature is negligible or reversed. Data & code: osf.io/q2wha/overview 7/7

We found little support for differences in 2D:4D ratios between groups defined by sexual orientation in either sex. When publication bias was modeled directly using Bayesian model-averaging of complementary publication bias adjustments, the evidence for this association substantially weakened. 6/7

However, they modeled publication bias as an all-or-none issue, oversimplifying the problem. We reanalyzed their data using robust Bayesian meta-analysis to incorporate multiple bias adjustments. 5/7

Importantly, their analyses found no evidence of publication bias for female sexual orientation but did for male sexual orientation, with effects remaining statistically significant after adjustment. 4/7

Recently, Swift-Gallant et al. (2025) conducted an updated meta-analysis on 2D:4D and sexual orientation, reporting more male-typical digit ratios in same-sex-oriented women and more female-typical ratios in homosexual men compared to heterosexual groups. 3/7

There’s been a long-standing claim that the ratio between the index and ring fingers (the 2D:4D ratio) reflects prenatal androgen exposure, and that this might relate to sexual orientation. 2/7

A serious failure case is that many biologists seem to have been taught that they should inspect bivariate correlations between predictors and not include pairs with high correlations. That is not even "collinearity" as statisticians define it (where is about joint info in additive model).