mulish vs perverse

mulish

adj
  • Characteristic of a mule; stubborn, obstinate, or intractable 

perverse

adj
  • Obstinately in the wrong; stubborn; intractable. 

  • Morally wrong or evil; wicked; perverted. 

  • Turned aside while against something, splitting off from a thing. 

  • Ignoring the evidence or the judge's opinions. 

  • Wayward; vexing; contrary. 

verb
  • To pervert. 

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