¶1{concurring). I concur with the majority decision, but I disagree with the majority’s reasoning that the admission of Thomas Bosman’s testimony was error. This issue has been raised in a variety of jurisdictions with contradictory results.
¶2A jury found Lew Jensen guilty of having sexual intercourse with his eleven-year-old stepdaughter. The state’s primary witness was the stepdaughter who testified that while she was living with her grandmother and Jensen, he got into bed with her, touched her vagina, and had sexual intercourse with her.
¶3*345On the other hand, Jensen denied having any sexual contact with his stepdaughter. Jensen testified that his former wife had left him for another man and had taken the daughter to California with her. He then obtained a court order granting him custody of his stepdaughter and brought her back to Wisconsin. Jensen claims that the stepdaughter fabricated the sexual assault charge as part of a plan with her mother in order that she might return to California.
¶4As a part of its case against Jensen, the state called Bosman, a guidance counselor at the stepdaughter’s school. The stepdaughter had first related to Bosman her accusations of sexual abuse three days after the alleged assault had occurred. Over objection, Bosman testified that the child’s acting out behavior subsequent to the alleged incident was consistent with children who were victims of child abuse. He did not directly express an opinion that she was telling the truth or that she was sexually assaulted.
¶5It is evident that his testimony does bolster her credibility, but this should not be a basis to deny the testimony. Much testimony, including expert testimony, tends to show that another witness either is or is not telling the truth. This, by itself, should not render evidence inadmissible. When an expert’s testimony, if believed, will help the jury understand the evidence or determine a disputed fact, it should be admissible at the trial court’s discretion. Section 907.02, Stats. Nor is testimony otherwise admissible in the form of an opinion or inference objectionable because it embraces an ultimate issue to be decided by the trier of fact. Section 907.04, Stats.
¶6Sexual abuse of a child is usually committed in a secluded place witnessed only by the victim and the assailant. Thus, the trial involves primarily the vic*346tim’s word against the accused’s. This presents a difficult question for the jury. The expert’s testimony is relevant to aid the jury in determining whether sexual abuse occurred. It should not be inadmissible simply because it may corroborate or make more credible the victim’s testimony.
¶7The use of expert testimony for the limited purpose of showing that a child’s actions were consistent with those of children who are victims of sexual abuse, where the accused denies any sexual contact, is not a dramatic departure from the normal use of expert testimony in trials. The trial court must first find that the witness is indeed an expert and is testifying on a subject that is proper for expert testimony. The court must also find that the offered testimony is relevant. Opposing counsel will then have the opportunity to discredit the testimony through cross-examination and show any possible bias. The jurors ultimately determine what weight should be given to the testimony. Here, the trial court considered these factors and reasonably exercised its discretion by admitting Bosman’s testimony.
¶8Kansas and Oregon have held that such evidence is admissible because it is relevant to the issues being litigated and would assist the jury in making its determination as to guilt or innocence. See, e.g., State v. McQuillen, 689 P.2d 822, 828 (Kan. 1984), aff’d, 721 P.2d 740 (1986); State v. Middleton, 657 P.2d 1215, 1221 (Or. 1983).
¶9On the other hand, Minnesota and Missouri have held that similar psychiatric evidence is inadmissible because it has not reached a level of scientific reliability necessary to establish the foundation for its admissibility. See, e.g., State v. Saldana, 324 N.W.2d 227, 229 (Minn. 1982); State v. Taylor, 663 S.W.2d 235, 239 (Mo. 1984). These jurisdictions have expressed grave reservations as to whether a logical correlation exists between the complainant’s subsequent behavior and the expert’s opinion that the complainant had been subjected to a sexual attack. These jurisdictions have also concluded that the prejudice resulting from bolstering the credibility of a complainant’s testimony with scientific dignity of a psychologist’s or a psychiatrist’s opinion outweighed the probative value of such evidence.
¶10It should be noted however that none of these jurisdictions would permit direct psychiatric or other expert testimony that the complainant was testifying truthfully.