intelligence vs level-headedness

intelligence

noun
  • The quality of making use or having made use of such capacities: depth of understanding, mental quickness. 

  • Information, often secret, about an enemy or about hostile activities. 

  • A political or military department, agency or unit designed to gather information, usually secret, about the enemy or about hostile activities. 

  • Capacity of mind, especially to understand principles, truths, facts or meanings, acquire knowledge, and apply it to practice; the ability to comprehend and learn. 

  • An entity that has such capacities. 

level-headedness

noun
  • The property of being level-headed. 

How often have the words intelligence and level-headedness occurred in a corpus of books? (source: Google Ngram Viewer )