A new study shows that people – men and women – can accurately judge another person’s fighting ability (based upon upper body strength) by looking at their face . . . http://www.sciencedaily.com/releases/2008/10/081022135809.htm . . . it seems that testosterone levels are shown through the bridge of the brows and the line of the chin and this correlates very very highly with upper body strength which would have been an indicator for fighting ability for pre-technological man.  The ability to judge these characteristics probably came over time as males needed to know when to back down or challenge someone without risking excessive and potentially deadly physical harm to themselves while females use the ability to judge which males are more likely going to be able to protect them or their offspring.

Neither sex is very good at judging the physical strength of women . . . most likely as most physical threats are caused by and taken care of by males in primitive cultures (as well as most modern ones).

All the best,
Brian 

Brian David Phillips, PhD, CH [brian@briandavidphillips.com]
Hypnotist, Hypnotherapist, Intuitionist, Trance Wizard
President, Society of Experiential Trance
Associate Professor, NCCU, Taipei, Taiwan
http://www.BrianDavidPhillips.com