Unless all men are considerd equally manly, and all women are considered equally womanly, and all people in between are ignored, it's obviously a spectrum. And if it's a spectrum, I don't see why it couldn't be fluid too. Most people probably don't move much along the spectrum during their lives, but some do, and I bet most move at least a bit.
Personally I'm not sure gender is even a very useful concept. Sex is more useful because in most cases it's easy to determine, but even it a spectrum (where most people just end up on the opposing ends). But gender... How do you even define it? How do you determine a person's gender?







