introspection vs thoughtfulness

introspection

noun
  • A looking inward; specifically, the act or process of self-examination, or inspection of one's own thoughts and feelings; the cognition which the mind has of its own acts and states 

thoughtfulness

noun
  • Thoughtful and considerate attention. 

  • Careful deliberation before action. 

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