646.21  Wanton aggression.
  In case of wanton aggression on the part of the defendant, the jury may award exemplary damages.
[C51, §2024; R60, §3597; C73, §3263; C97, §4200; C24, 27, 31, 35, 39, §12250; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §646.21]