altruism vs kindness

altruism

noun
  • Regard for others, both natural and moral without regard for oneself; devotion to the interests of others; brotherly kindness. 

  • Action or behaviour that benefits another or others at some cost to the performer. 

kindness

noun
  • An instance of kind or charitable behaviour. 

  • The state of being kind. 

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