[Male] Larger [Female] Smaller [Features] 
Size
W e i g h t
S i z e
C a p a c i t y
W a l l s
M u s c u l a r r i d g e s , g l a b e l l a , M a s t o i d p r o c e s s e s , S u p e r i o r n u c h a l l i n e s
T y m p a n i c p l a t e
S u p r a o r b i t a l m a r g i n
F o r e h e a d
V a u l t
C o n t o u r o f f a c e