An Isolated, Implausibly Large Effect in a Case-Control Study of Digit Ratio (2D:4D) and Male Androgenetic Alopecia: Comment on Unal
February 2021
TLDR Digit ratio likely doesn't predict male hair loss.
The document commented on a study that reported a significant association between digit ratio (2D:4D) and male androgenetic alopecia (AGA), specifically noting an isolated effect with the left-hand 2D:4D ratio. However, the cumulative research evidence suggested that such associations were either negligible or nonexistent, indicating that 2D:4D was most likely not an indicator of male AGA. The document highlighted concerns about the validity of the reported effect, suggesting it might be an exaggeration or a false positive, and emphasized the importance of research integrity and reproducibility in scientific studies.