Simon Baron-Cohen has theorized that autistic spectrum conditions may be a manifestation of an extreme male, or systemizing, brain. Some researchers point to the fact that newborn boys make less eye contact than newborn girls. If I am not mistaken, autistic children had more testosterone in utero. Testosterone also initiates the biophysiological development known as virilization (developing masculine features). In Wikipedia, the Testosterone article mentions "advanced postnatal effects" (at puberty): Among these are facial hair, chest hair, deepened voice, changed face contours, and increased muscle mass.
I remember seeing a special on the Discovery Channel about faces, and they mentioned masculine and feminine faces. Women preferred men with highly masculine features for short-term relationships but men with somewhat more androgynous features for more stable relationships. The researchers also measured people's impressions of trustworthiness. Highly masculine faces were rated less trustworthy. One example was President Bill Clinton; they used edited an image of Bill Clinton with larger eyes to test whether that improved his ratings of perceived trustworthiness. It did, even among Republicans! Another experiment tested women's impressions of both attractiveness and dominance for faces (control and edited for higher testosterone features). Testosterone level did not affect attractiveness; however, testosterone level did affect perception of dominance (as a personality trait).
Do you (man or woman) show features of higher-than-normal testosterone levels for your sex?
My level of testosterone is probably in the normal range for twenty-year-old men, but my guess is it is above average by at least a little. I have a very definite "square jaw" and heavy brow. Another thing is high-testosterone faces are more elongated, rectangular, than oval. The change from childhood is striking.