What did the 2011 Andrology/International Journal of Impotence Research studies find about hand or foot size and penis size?
Executive summary
Two peer‑reviewed 2011 papers arrived at different, specific conclusions: an Asian Journal of Andrology study reported a statistically significant correlation between the second‑to‑fourth digit ratio (2D:4D) and adult penile length, suggesting prenatal androgen exposure links finger‑ratios and penile growth [1] [2], while an International Journal of Impotence Research paper examining >2,200 young Turkish men found at best weak or inconsistent correlations between standard body measurements (height, foot size, weight, BMI) and penile dimensions [3] [4]. Subsequent systematic review work places the strongest and most consistent correlation with height, not hand or foot size, and stresses that any correlations reported are typically weak and clinically unreliable [5] [6].
1. The 2D:4D (digit‑ratio) finding: a hormonally plausible but not definitive link
A 2011 study published in the Asian Journal of Andrology tested the hypothesis that the ratio of the index to ring finger (2D:4D)—an indirect marker proposed to reflect prenatal testosterone exposure and androgen‑receptor sensitivity—predicts adult penile length, and reported a statistically significant association consistent with that biological model [1] [2]. The study’s logic rests on known roles for prenatal androgens in genital development, and the authors concluded the digit ratio correlated with penile length in their sample [1] [2]. That finding is mechanistically plausible, but the paper reports an association in a discrete study population rather than proof of a universal, strong predictor.
2. The large somatometric study in International Journal of Impotence Research: weak or no simple predictors
A contemporaneous paper in the International Journal of Impotence Research measured flaccid, stretched and erect penile size in 2,276 healthy young Turkish men and tested correlations with somatic measures; the results showed only weak correlations between penile length and common anthropometric parameters and did not support reliable prediction from hand or foot size [3] [4]. The authors’ data and later citations emphasize that while small, statistically significant correlations may appear for some measures in some cohorts, they are not strong or consistent enough to allow accurate prediction of penile length from foot or hand size [3] [4].
3. What later reviews and meta‑analyses say: height trumps hands and feet; correlations are modest
Systematic reviews and nomograms compiling tens of thousands of measurements find the most consistent, albeit modest, correlation between penile length (stretched or erect) and height (correlation coefficients broadly in the range r = 0.2–0.6), while correlations with foot length, hand size or other somatic measures are inconsistent and generally weak [5] [6]. The reviewers explicitly cite the 2011 studies (including Choi et al. and the Turkish cohort) and conclude that simple anthropometric proxies—foot or hand length—do not reliably predict penis size across populations [6] [4].
4. Methodological limits that shape—and limit—interpretation
Measurement variability, population differences, and technique matter: penile measurements differ by whether flaccid, stretched or erect length is used and by the method and examiner, creating noise that can produce spurious correlations in small samples; the literature repeatedly flags measurement technique and accuracy as central limitations [7] [8]. The digit‑ratio finding, while biologically plausible, depends on 2D:4D as an imperfect proxy for prenatal androgens and was shown in specific cohorts rather than across diverse populations [1] [2]. Systematic reviews therefore downgrade the practical predictive value of these markers despite some statistically significant associations [5] [4].
5. Final verdict: some signals, no simple rule—media hype fills in the gaps
The 2011 Asian Journal of Andrology paper reported a link between 2D:4D and penile length that fits a hormonal-development model [1] [2], while the 2011 International Journal of Impotence Research data from thousands of men showed only weak, unreliable correlations between penile size and broadly used somatic measures like foot or hand size [3] [4]; pooled evidence and reviews favor height as the most consistent—but still imperfect—predictor [5] [6]. Popular summaries often oversimplify or overstate these findings—turning modest, population‑specific statistical associations into deterministic myths—whereas the scientific record supports neither a simple nor universally applicable shortcut for predicting penis size from hands or feet [9] [6].