4.07 Credibility of Special Categories of Witnesses and Weight of Evidence The committee recommends that no instructions on the credibility of special categories of witnesses be given. Comment This instruction was formerly IPI 2.09. Although instructions of this type have been approved, the committee recommends that no instruction be given as to credibility of special categories of witnesses, such as employees, experts and lawyers. See the Comment at 4.08 infra, as to expert witnesses. These seem to be simply matters of fact for the jury and do not involve legal rules. Unless we are to allow the judge to comment in detail on each witness, it seems wiser to leave these matters to be argued to the jury by counsel. The court in Department of Pub. Works & Bldgs. v. Tinsley, 120 Ill.App.2d 95, 256 N.E.2d 124 (5th Dist. 1970), stated that due to the IPI committee's recommendation that an instruction on this subject should not be given a tendered instruction on this subject was properly refused. In Stach v. Sears, Roebuck & Co., 102 Ill.App.3d 397, 429 N.E.2d 1242, 57 Ill.Dec. 879 (1st Dist. 1981), the court cited with approval the committee's comments to this instruction in holding that the trial court properly refused to give an instruction to the effect that the testimony of an attorney on behalf of his own client is to be given little weight. In affirming the committee's position that instructions such as former IPI 2.09 should not be given, it stated that "unless we are to allow the judge to comment in detail on each witness, it seems wiser to leave these matters to be argued to the jury by counsel."