Men are pinheads

There has been research where people are asked to scale a representation of a human in proportion to their bodies. Women make eyes, thighs and bottoms too big, men do that to the upper torso and arms, but minimize the size of the head and legs. It is theorized that we tend to enlarge in our minds that which is significant to us and minimize that which is less important.

Whatever the reason, huge boobs or chest and a tiny head and legs are, in my experience, a reliable indicator of a female avatar operated by men that haven't studied art (and proportion) or anatomy, and when they make male avatars, they copy the minotaur (showing it is nothing new) and do the same which is why most men in SL look like barrels perched on toothpicks. Women get heads and boobs right because we look at faces a lot and know how uncomfortable a big bust can be, but women untrained in proportion tend to make thighs and bottoms too big.

This usually is a reliable way to determine visually the sex of the creator of an avatar shape. Of course, the creator is not necessarily the operator, and If you can't figure out the difference visually or in chat inside a few minutes (big clue, irrespective of avatar gender, guys tend to want to get into your panties - and find Lolita outfits irresistable) , then it probably doesn't matter very much. Avatars have no DNA.

Inspiration:

You know, I think I will release a tpv that has the microphone always on, and then broadcasts to a search bot people whose avs don't match their gender so they can be banned. I think it would sell pretty well. [I was being snarky, because the only thing that generates more over the top reactions than copybotting]