headstrong vs obstinate

headstrong

adj
  • Determined to do as one pleases, and not as others want. 

obstinate

adj
  • Stubbornly adhering to an opinion, purpose, or course, usually with implied unreasonableness; persistent. 

  • Typical of an obstinate person; fixed and unmoving. 

  • Not easily subdued or removed. 

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