[piercehawkeye45]

This got me thinking so I want to add a few more thoughts.

Going off the evolved thought, another way of determining what traits could be biologically defined as manly would be looking at what traits that women find attractive in men. There are certain traits that both men and women evolved to find attractive, and these traits should be the ones that describe the "fittest" men and women. The traits that will lead to the most successful offspring.

For men, what I've noticed is that women tend to find men with confidence, social status (how this person is viewed within a group), and personal drive extremely attractive. This can take many different forms and these traits match up well with someone who would lead a hunter-gatherer society. I would consider these biological traits of manliness.

Other forms of manliness, being able to throw a spiral with a football for example, is purely sociological. This will change depending on the society.