The Collaborative International Dictionary of English v.0.48:

Mentality \Men*tal"i*ty\, n.
   Quality or state of mind. "The same hard mentality."
   --Emerson.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mentality
    n 1: a habitual or characteristic mental attitude that
         determines how you will interpret and respond to situations
         [syn: mentality, outlook, mindset, mind-set]
    2: mental ability; "he's got plenty of brains but no common
       sense" [syn: brain, brainpower, learning ability,
       mental capacity, mentality, wit]