Signs of weakness, like nail biting and adult braces, can be impossible to hide, which is why you have to overcompensate with signs of strength. Making direct and constant eye contact, flexing your jaw muscles and consuming excessive amounts of undercooked meat are all harbingers of your virility and therefore superiority.
Demonstrating weakness and strength at the same time makes you seem unhinged, which is working out well for Charlie Sheen.
