Agreed. Exactly. You need a good amount of testosterone to build muscle. Women naturally do not have much testosterone compared to men (generally). Hence, it's a lot harder to build muscle for a woman (naturally). :) Now of course using steroids, you could overcome that natural barrier, but yeah. And of course, there are some exceptions. Some women have more testosterone, sometimes even equal to an average man. So for them muscle may be built more easily. But my guess is that they tend to look "manlier" as well. So it's easier to tell when this is the case.