cold feet vs pessimism

cold feet

noun
  • A feeling of nervousness or anxiousness causing one to reconsider a decision about an upcoming event. 

  • Used other than figuratively or idiomatically: see cold, feet. 

pessimism

noun
  • A general belief that bad things will happen. 

  • The condition of being pessimal. 

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

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