Is it masculine not to cry?

To be frank, I cannot cry. It is a rarity for me. I have an impressive emotional threshold. Even looking at images of the holocaust, having someone close to me pass away, you know all those things that get most folk to tears - doesn't move me. I often wonder why that is. I have a habit of intellectualizing these things, always try to remove emotion from the issue etc. I have another female friend that is the same. We are told that we are callous ice hearted people because of this. And it got me thinking... Is it a masculine trait? This type of stoicism?