self-serving vs unkindness

self-serving

adj
  • Showing interest only in oneself (pursuing self-interest to the exclusion of other goals). 

unkindness

noun
  • The state or quality of being unkind. 

  • An unkind act. 

  • The collective noun for ravens 

How often have the words self-serving and unkindness occurred in a corpus of books? (source: Google Ngram Viewer )