Evidence of habit may take the form of specific instances of conduct, opinion, or any other type of evidence otherwise permitted by the Federal Rules of Evidence.

Gass v. Marriott Hotel Services, Inc., 558 F.3d 419, 426 (6th Cir. 2009) ("Under Daubert, before allowing an expert's testimony to be considered by the jury, a trial court should consider: ? (1) whether the reasoning or methodology underlying the expert's testimony is scientifically valid; and (2)...A field or method that is offered as as a scientific field or method satisfies the requirements for the admissibility of evidence under Federal Rule 702 or a comparable State rule only if the field or method is shown to be genuinely scientific.

Michelson v. United States, 335 U.S. 469, 476 (1948) (The "line of inquiry firmly denied to the State is opened to the defendant because character is relevant in resolving probabilities of guilt.[11] He may introduce affirmative testimony that the general estimate of his character is so favorable that the...A criminal defendant may offer a pertinent trait of his or her character circumstantially -- to show the defendant's doing or non-doing of a specific act.

United States v. Perlmuter, 693 F.2d 1290, 1294 (9th Cir. 1982) (reversing conviction for knowingly procuring naturalization contrary to law because the trial court erred in admitting Exhibit 4 [which indicated that....There is a hearsay exception for evidence of a final judgment, entered after a trial or upon a plea of guilty (but not upon a plea of nolo contendere), adjudging a person guilty of a crime punishable by death or imprisonment in excess of one year, to prove any fact essential to sustain the judgment, but not including, when offered by the Government in a criminal prosecution for purposes other than impeachment, judgments against persons other than the accused.