heartlessness vs sensitivity

heartlessness

noun
  • the characteristic of being heartless 

sensitivity

noun
  • The degree of response of an instrument to a change in an input signal. 

  • The degree of response of a film etc. to light of a specified wavelength. 

  • The ability of an organism or organ to respond to external stimuli. 

  • The quality or state of being sensitive; sensitiveness. 

  • Vulnerability to medical treatment: Synonym of susceptibility. 

  • The probability, in a binary classification test, of a true positive being correctly identified. 

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