force of habit

English edit

force of habit (countable and uncountable, plural forces of habit)

(idiomatic) an act that has been repeated to the point where the performance of the act becomes automatic
"Only force of habit will explain why people today do honor to Christopher Columbus." - New York Times, 1937
- 1900 May 17, L[yman] Frank Baum, The Wonderful Wizard of Oz, Chicago, Ill., New York, N.Y.: Geo[rge] M. Hill Co., →OCLC:
  The Tin Woodman lay down on his bed from force of habit, for he remembered when he was made of flesh; but not being able to sleep, he passed the night moving his joints up and down to make sure they kept in good working order.

automatic act