stupid is as stupid does

stupid is as stupid does

One's actions indicate one's level of stupidity (or intelligence). The phrase was popularized by the film Forrest Gump. Of course that fool backed his car into own house! Stupid is as stupid does! Stupid is as stupid does, so judge her on her actions, not your first impression.
See also: does, stupid
Farlex Dictionary of Idioms.
See also:
  • (one's) day in court
  • at will
  • better (to be) safe than sorry
  • better safe than sorry
  • (there's) no peace/rest for the wicked
  • at (one's) doorstep
  • at doorstep
  • (one's) jig is up
  • at (one's) expense
  • at somebody's expense