Men and women usually have different hand proportions, index/ring finger ratio in particular (2D:4D). It's been found to be linked to prenatal testosterone levels during early parts of brain development, with low 2D:4D related to higher prenatal testosterone exposure. There are many scientific articles out there (of varying quality) showing statistical links between 2D:4D ratio and male/female behavior patterns.

This might be a little bit sensitive, but I'm going to step aside from political taboo just because I find it interesting. Here are some articles as an example:

A study where feminist women were found to have a more masculine distribution of index/ring finger ratio: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4158978/

Correlation between masculine index/ring ratio and crimes: https://www.researchgate.net/publication/256466184_Criminality_and_the_2D4D_Ratio

Female rowers with more masculine 2D:4D tend to perform better: https://pubmed.ncbi.nlm.nih.gov/25242253/

2D:4D ratio does not predict current levels of testosterone for adult men: https://pubmed.ncbi.nlm.nih.gov/32572079/

Low 2D:4D linked to choice of judo/boxing instead of aerobics: https://www.cambridge.org/core/journals/journal-of-biosocial-science/article/sports-preference-and-digit-ratio-2d4d-among-female-students-in-wroclaw-poland/6AD5C8B045056C2C3AFB3291358B07F4

I thought it would be interesting to create a thread where people can share their perspectives on this. The reason is that I'm affected by it personally - I'm male with a digit ratio of 1.04. I'm not part of any of the sexual minorities, but I often feel "dyslexic" with behavior patterns related to masculinity. During childhood the timing of my growth was much earlier than what's normal for boys, and I can do the "chair challenge" without any effort.

Anyone here who has worked with studying 2D:4D, or someone who has anecdotes about yourself or someone you know?