In Weil v. Seltzer, 873 F.2d 1453, 1459-60, 277 U.S. App. D.C. 196 (D.C. Cir. 1989), the appellant offered testimony of five former allergy patients to whom the appellee physician prescribed steroids, but represented to them that the drugs were antihistamines or decongestants.
The trial court admitted the testimony over objection as habit evidence under FRE 406. Id. at 1460. The D.C. Circuit, reviewing the trial court's ruling under an abuse of discretion standard, held that the district court abused its discretion in allowing the former patients' testimony under FRE 406. Id.
The D.C. Circuit explained:
Rule 406 allows certain evidence which would otherwise be inadmissible if it rises to the level of habit. In this context, habit refers to the type of nonvolitional activity that occurs with invariable regularity. It is the nonvolitional character of habit evidence that makes it probative. See, e.g., Levin v. United States, 338 F.2d 265, 272, 119 U.S. App. D.C. 156 (D.C. Cir. 1964) (testimony concerning religious practices not admissible because "the very volitional basis of the activity raises serious questions as to its invariable nature, and hence its probative value"), cert. denied, 379 U.S. 999, 85 S. Ct. 719, 13 L. Ed. 2d 701 (1965). But see Perrin v. Anderson, 784 F.2d 1040, 1046 (10th Cir. 1986) (five instances of violent encounters with police sufficient to establish "habit" of reacting violently to uniformed police officers). Thus, habit is a consistent method or manner of responding to a particular stimulus. Habits have a reflexive, almost instinctive quality. The advisory committee notes on Rule 406 illustrate this point:
A habit . . . is the person's regular practice of meeting a particular kind of situation with a specific type of conduct, such as the habit of going down a particular stairway two stairs at a time, or of giving the hand-signal for a left turn, or of alighting from railway cars while they are moving. The doing of habitual acts may become semiautomatic. (Weil, 873 F.2d at 1460.)
The court in Weil also noted that to determine whether conduct rises to the level of "habit," a court must consider the "'adequacy of sampling and uniformity of responses.'" Id.