Sexual dimorphism in digit-length ratios of laboratory mice.
Level 5 - mechanism / opinion, no new human data
Non-clinical animal research (CEBM level 5).
PubMed 12115273 · doi:10.1002/ar.10108
What was done
Researchers measured the second-to-fourth digit length ratio (2D:4D) on the left and right rear paws of adult and prepubescent weanling outbred laboratory mice to determine if sexual dimorphism in digit ratios occurs in non-human mammals.
What was found
The abstract reports no numerical values, variances, or statistical test results. It states that female mice had a larger 2D:4D ratio in the right rear paw compared to males, an effect also observed in prepubescent weanling mice.
Why it matters
Demonstrating that sexually dimorphic digit ratios exist in mice suggests this trait may be conserved across mammals, potentially providing an animal model to experimentally investigate how prenatal androgens influence peripheral anatomy.
Limits
The abstract does not disclose sample sizes, exact ratio values, effect magnitudes, or statistical thresholds. Dimorphism was only detected in the right rear paw, and animal anatomical patterns do not directly translate to human clinical or behavioral associations.
Cited by
- supports A sex difference in the 2D:4D digit ratio is present in mice.