What, in precise terms, creates a "rugged" face?

Please note: the term “rugged” is (at least in this case) exclusively used for males or in a masculine sense.

There is a general consensus that (based upon my reading around and popular magazines) a rugged face consists of deep-set eyes, a square-ish jaw and thick, low eyebrows.

But how do humans (in general) come to this assessment? Is it something that is hard-wired into our biological systems? Why would this be so?

One strand of thought comes to mind when I read this. It could be (or most likely is) about male dominance. Put simply, a rugged face gives a more domineering impression.

What’s the straight dope on this? How do we define “rugged” (especially with respect to a “rugged” face?)? Can we precisely say what determines its overall appearance (e.g. is it a set of dark eyes, broad nose etc.)? Why do these types of faces appear more dominant or leaderly (I know one hypothesis - mentioned in the article - possibly has to do with greater levels of testosterone)?

And do these norms spread evenly across the globe (i.e. different ethnic/cultural/geographic groups)? Does a rugged face from Sudan appear rugged to Westerners? Are certain types of faces (from certain places) considered universally rugged? And what type of face is considered the most rugged by all (for example, would Sudanese faces universally be considered more rugged than French faces?)?

–This last one interests me because what we normally consider “rugged” we apply (at least IMO) to more Westernised - read European - faces.–

Stubble. Definitely stubble.

The Sun.

Seriously. It takes a lot of exposure to get “rugged”.

I think it’s most often applied to masculine, older movie actors who are wrinkled but still look good. They’re rugged like a well-worn piece of canvas.

Definition of rugged good looks.