contemplation vs introversion

contemplation

noun
  • The act of contemplating; musing; being highly concentrated in thought 

  • The act of looking forward to a future event 

  • Holy meditation. 

  • The state of being considered or planned. 

introversion

noun
  • The action of turning one's thoughts upon internal or spiritual matters. 

  • Arrangement of two similar words, lines, etc. to form the middle part of a structure. 

  • A turning inward 

  • A personality orientation towards the self and mental abstraction; behavior expressing such orientation. 

How often have the words contemplation and introversion occurred in a corpus of books? (source: Google Ngram Viewer )