navel-gazing vs soul-searching

navel-gazing

noun
  • Excessive focus on oneself; self-indulgent introspection. 

  • (Disproportionate) concentration on a single issue. 

  • Contemplation of one's navel as an aid to meditation. 

soul-searching

noun
  • Probing introspection; a critical consideration of one's conscience; also, an instance of such consideration. 

adj
  • Involving probing introspection, or a critical consideration of one's conscience, especially motives and values. 

How often have the words navel-gazing and soul-searching occurred in a corpus of books? (source: Google Ngram Viewer )