pitiless vs unsociable

pitiless

adj
  • having no kindly feelings; unkind 

  • having, or showing, no pity; merciless, ruthless 

unsociable

adj
  • unfriendly 

  • not congenial or compatible 

  • not desiring the company of others 

noun
  • A person who is not sociable. 

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