The below post is misleading. I was an author on the year 2000 paper re this in @Nature (r

Well SupportedMasculinizing effects of hormones in fetal development can be a consequence of testosterone being converted into estrogen.

Partially SupportedTestosterone levels are indicated by the 2D:4D digit ratio.

Partially SupportedTestosterone is converted by the enzyme 5-alpha-reductase to dihydrotestosterone, which controls penis growth.

Partially SupportedA longer ring finger compared to the index finger is associated with higher baseline testosterone levels, increased risk-taking, assertiveness, drive, stronger spatial and physical performance, greater dominance behavior, and competitive instinct.

Not Supported