Psychology Paradigm Challenge

That old scientific link between your finger length and who you're into? It pretty much disappears once you clear out the biased data.

March 18, 2026

Original Paper

Little evidence for group differences in 2D:4D ratios based on sexual orientation after adjusting for publication bias

Victor Kenji M. Shiramizu, František Bartoš, Benedict C. Jones, Thomas V. Pollet

PsyArXiv · 3dcth_v3

The Takeaway

For years, the '2D:4D ratio' (the difference in length between your index and ring fingers) was cited as a biological marker for prenatal hormone exposure and sexuality. This re-analysis suggests that the effect was mostly an illusion created because researchers were only publishing studies that found a link while burying those that didn't.

From the abstract

The ratio between the lengths of the second and fourth digits (2D:4D) has been proposed as a putative marker of prenatal androgen exposure and investigated for its potential link to sexual orientation. In a recent updated meta-analysis, Swift-Gallant et al. (2025) reported more male-typical digit ratios in same-sex-oriented women than in heterosexual women, while homosexual men showed more female-typical ratios than heterosexual men. Their analyses found no evidence of publication bias for femal