negativity vs pessimism

negativity

noun
  • The characteristic of being pessimistic or contrarian. 

  • Negative sentiment. 

  • The characteristic of having a negative charge. 

pessimism

noun
  • The condition of being pessimal. 

  • A general belief that bad things will happen. 

  • The doctrine that this world is the worst of all possible worlds. 

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