Appellant Ryan James Eff (“Eff’) appeals his conviction on three counts of arson in violation of 18 U.S.C. § 844(f)(1) and (2), asserting that the district court erred by excluding the testimony of his two expert witnesses supporting his insanity defense. We affirm the conviction because when considering the appropriate reach of the expert testimony and other evidence in the light most favorable to Eff, the evidence was insufficient to warrant a jury instruction on insanity.
I.
Eff worked as a firefighter for the United States Forest Service (“USFS”). Beginning in May 2005, twenty-three different fires were intentionally set in the Davy Crockett National Forest, where Eff was principally assigned to fight fires. USFS Special Agent Gary McLaughlin was investigating these fires and received information making Eff a suspect in the case. Agent McLaughlin, therefore, secretly installed a Global Positioning System (“GPS”) data logger on Effs USFS vehicle. Based on the data from the GPS, Agent McLaughlin placed Effs vehicle at the point of origin in three subsequent forest fires.
Considering Eff their prime suspect, Agent McLaughlin and Captain David Norsworthy interviewed Eff about the fires. Although Eff initially denied setting the fires, he eventually confessed to starting fifteen to twenty of the forest fires. Eff set the fires because he was angry that he was not being given an opportunity to advance in his job, he received increased experience in fighting the fires he had started, and he hoped this experience would qualify him for a promotion. Moreover, Eff received extra compensation when fighting fires.
Eff was charged with three counts of arson in violation of 18 U.S.C. § 844(f)(1) and (2).1 Eff gave timely notice of his intent to present an insanity defense. He identified two expert witnesses to testify about a neurogenetic defect he has — Kline-felter’s Syndrome- — and its effect on his ability to appreciate the nature and quality or wrongfulness of his acts. On October 11, 2006, the district court held a Daubert hearing to consider the admissibility of the expert evidence regarding Effs condition. After hearing the proffered expert testimony, the district court concluded that the experts’ testimony should be excluded and, *715accordingly, refused to give a jury instruction on the insanity defense.
Eff thereafter waived his right to a jury trial and proceeded to try the case pursuant to stipulated facts, disputing only that his acts of arson created a substantial risk of injury to the responding firemen. The district court found Eff guilty on all three counts of arson and sentenced him to the statutory minimum of seven years in prison. Eff now appeals the district court’s exclusion of his expert testimony.
II.
The federal statute governing the insanity defense provides as follows:
(a) Affirmative defense.—It is an affirmative defense to a prosecution under any Federal statute that, at the time of the commission of the acts constituting the offense, the defendant, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality or the wrongfulness of his acts. Mental disease or defect does not otherwise constitute a defense.
(b) Burden of proof.—The defendant has the burden of proving the defense of insanity by clear and convincing evidence.
18 U.S.C. § 17(a), (b). The burden thus rests on the defendant asserting an insanity defense “to show by ‘clear and convincing evidence’ that he is not guilty by reason of insanity.” United States v. Dixon, 185 F.3d 893, 403 (5th Cir.1999).
III.
The government does not dispute that Eff has been diagnosed with Klinefelter’s Syndrome, a disorder resulting from an additional X chromosome in a male’s DNA. Eff proffered two expert witnesses, Dr. Carole Samango-Sprouse, Ph.D, and Dr. Kyle Boone, Ph.D, both experts in the field of neurogenetic disorders, including Kline-felter’s Syndrome, to testify about Effs Klinefelter’s Syndrome and its effects on his behavior.
A. Dr. Carole Samango-Sprouse
Dr. Samango-Sprouse is an expert in the neurodevelopmental assessment of children, specializing in genetic disorders. Her opinion relied heavily on a battery of tests conducted by Dr. Boone and interviews with Eff and his mother.
During the Daubert hearing, Dr. Saman-go-Sprouse first testified about Klinefel-ter’s Syndrome and its general effects. Specifically, she testified that: Klinefel-ter’s Syndrome is a neurogenetic disorder, which is a genetic condition that, from birth, causes brain, behavioral, and neuro-cognitive differences; untreated Klinefel-ter’s Syndrome causes deficient levels of testosterone in adolescent males, affecting brain development; young adolescents with Klinefelter’s Syndrome have decreased volume in the frontal lobe of their brains, which controls executive functioning; the primary components of executive functioning are inhibition, attention, and working memory; executive functioning controls the ability to identify, plan, and execute a course of action; persons with Klinefelter’s Syndrome and deficits in executive functioning show deficits in their ability to plan, their ability to anticipate and appreciate the consequences of their actions, and their ability to inhibit inappropriate behavior, resulting in “childlike decisions” or “magical thinking”; and Kline-felter’s Syndrome resulting in executive dysfunction can constitute a severe mental disease or defect.
Dr. Samango-Sprouse next testified about the effect of Klinefelter’s Syndrome on Effs behavior, specifically his decision to set the fires in Davy Crockett National Forest. She stated that: the tests by Dr. *716Boone reveal that Eff was deficient in executive functioning and his ability to make judgments and understand consequences; Eff makes judgments similar to an eight-year-old child; and when Eff set the fires, he was not thinking about the consequences or wrongfulness of his actions — he was “busy on the front part of the plan” and “was focused on showing that he could put out a fire” so he could impress his supervisor. Dr. Samango-Sprouse concluded that Eff was unable to appreciate the nature, quality, and wrongfulness of his acts.
B. Dr. Kyle Boone
Dr. Boone runs the neuropsychology testing service at Harbor-UCLA Medical Center. She evaluated Eff with numerous tests designed to measure the functioning of his frontal lobes. Dr. Boone only briefly reviewed Effs case history, relying on Effs test results for her conclusions.
Dr. Boone testified that: the tests she administered to Eff measured executive skills; executive skills are higher-level thinking skills, like organization, planning, thinking through consequences, problem solving, and picking the best solution to a problem; although Effs IQ is within normal limits, his scores on some of the executive functioning tests were equivalent to those of a mentally retarded or borderline mentally retarded person; the tests Eff did poorly on measured the ability to stop a behavior that is not appropriate to the situation, the ability to generate ideas and solutions to problems, and the ability to keep track of two different sources of information at once; Eff approaches problems similar to a ten-year-old or twelve-year-old child; and Eff has deficits in his ability to think through the consequences of his behavior. Dr. Boone concluded that Eff was suffering from a severe mental defect and was unable to appreciate the nature, quality, and wrongfulness of his acts.
IV.
The district court found Effs expert testimony inadmissible under Federal Rules of Evidence 702 and 403. Neither the government nor the district court questioned the expertise, qualifications, or methodology of Effs expert witnesses. The underlying basis of the district court’s conclusion was the disconnect between the experts’ analysis of Effs Klinefelter’s Syndrome and their stated conclusions that Eff — as a result of his condition — was unable to appreciate the nature and quality or wrongfulness of his acts. See United States v. Eff 461 F.Supp.2d 529, 533-37 (E.D.Tex.2006).
The district court’s analysis, however, did not take into account Federal Rule of Evidence 704(b), which states:
No expert witness testifying with respect to the mental state or condition of a defendant in a criminal case may state an opinion or inference as to whether the defendant did or did not have the mental state or condition constituting an element of the crime charged or of a defense thereto. Such ultimate issues are matters for the trier of fact alone.
Fed.R.Evid. 704(b). Where a defendant asserts an insanity defense, “the ultimate issue is whether at the time of the crime the defendant appreciated the nature and quality or the wrongfulness of his acts.” United States v. Levine, 80 F.3d 129, 134 (5th Cir.1996) (internal quotation marks and citation omitted). An expert is thus prohibited from testifying that a severe mental disease or defect does or does not prevent a defendant from appreciating the nature and quality or wrongfulness of his acts. Dixon, 185 F.3d at 400. Therefore, Dr. Boone’s and Dr. Samango-Sprouse’s testimony regarding their conclusions that Eff — at the time he committed the relevant acts of arson — was unable to appreci*717ate the nature and quality or wrongfulness of his actions is inadmissible at trial under Federal Rule of Evidence 704(b).
Given that this testimony is inadmissible, the question becomes whether the district court erred in excluding the experts’ “other” testimony—that is, testimony regarding Klinefelter’s Syndrome and its effect on Effs behavior (other than testimony regarding the ultimate conclusion). Because this “other” testimony goes to Effs mental condition at the time he committed the acts of arson, it is clearly relevant to Effs asserted insanity defense. Furthermore, the district court properly found no problems with the reliability of this “other” expert testimony under Rule 702. Thus, this testimony should have gone before the jury unless it was insufficient to warrant a jury instruction on insanity.2 Therefore, the decisive issue in this case is whether such testimony was sufficient to warrant a jury instruction on Effs insanity defense.3 Because “sufficiency of the evidence is generally considered a legal issue,” we review the district court’s refusal to give a jury instruction on insanity as a question of law de novo,4 Dixon, 185 F.3d at 403 (internal quotation marks omitted).
A jury instruction on the insanity defense is required “when the evidence would allow a reasonable jury to find that insanity has been shown with convincing clarity.” Id. at 404 (internal quotation marks omitted). This standard does not require a defendant to “eliminate ambiguity from his proof or to instill certainty in the minds of the jurors” but rather only requires that the evidence “would permit the jury to find to a high probability that defendant was insane.” Id. (internal quotation marks and citation omitted) (emphasis added). Additionally, out of deference to the jury’s role, a court “must construe the evidence most favorably to the defendant” when deciding whether to submit the insanity defense to the jury. Id. A court may, however, “withhold the insanity instruction if it concludes that the relationship between a defendant’s mental illness history and his criminal conduct has not been explained or examined in any meaningful way.” Id. at 407; United States v. West, 962 F.2d 1243, 1247-48 (7th Cir.1992) (“A judge may take this decision from the jury, like any other, if the admissible evidence ... would not permit a reasonable jury to return a verdict of insanity.”).
V.
Ignoring the experts’ testimony on the ultimate issue and construing Effs *718“other” evidence supporting his insanity defense in the light most favorable to Eff, we conclude that such evidence was insufficient to warrant a jury instruction on his insanity. Even assuming that Effs experts sufficiently established that his Kli-nefelter’s Syndrome constituted a “severe mental disease or defect,” Effs expert testimony was insufficient to permit a rational jury to conclude, by clear and convincing evidence, that he was unable to appreciate the nature and quality or wrongfulness of his actions.
At best, Effs expert testimony only establishes that Eff had a diminished capacity to understand and anticipate the consequences of his actions,5 that he was not focused on the wrongfulness or the consequences of his acts of arson, and that Eff makes judgments similar to an eight-year-old child. This evidence establishes only that Eff may have had a diminished, capacity to appreciate the nature and quality or wrongfulness of his actions, not that he was completely unable to appreciate such things, as required by 18 U.S.C. § 17.
In fact, the undisputed evidence shows that Eff was able to appreciate the nature, quality, and wrongfulness of his actions. First, with respect to Effs ability to appreciate the nature and quality of his acts, Eff knew what he was doing — setting fires — and, as a USFS fireman, he knew the damage and harm that fires could cause.6 Second, with respect to Effs ability to appreciate the wrongfulness of his acts, the evidence shows that Eff had the ability to and did appreciate that his actions were wrong. Eff set the fires in secret and initially attempted to cover up his involvement by lying to investigators. See United States v. Barton, 992 F.2d 66, 69 (5th Cir.1993) (“[A] person’s attempt to hide his commission of a crime suggests that the person knows the action is wrongful or illegal....”). Furthermore, in his confession, Eff indicated that he set the fires, in part, to retaliate against his superiors for denying him opportunities to advance at the USFS, and this motivation demonstrates that Eff knew that his actions were wrong.7 Finally, given that Eff was employed by the USFS to put out fires and knew firsthand the dangerousness of fires, the assertion that Effs Kline-felter’s Syndrome completely prevented him from knowing that setting fires was wrong seems incredible. Although Dr. Sa-mango-Sprouse stated that Eff was unable to appreciate the wrongfulness of his actions, her substantive testimony further indicates that Eff was in fact able to tell right from wrong. Dr. Samango-Sprouse testified that Eff appreciates that his con*719duct was wrong as an eight-year-old child appreciates that stealing is wrong — they can articulate that their actions were wrong, but they will complete the act anyway.8
Moreover, it appears that Effs insanity defense is the type of legal excuse that Congress sought to exclude when it “deleted the Volitional prong’ of the commonly accepted Model Penal Code approach which had permitted acquittal if the defendant ‘as a result of mental disease or defect ... lacks substantial capacity ... to conform his conduct to the requirements of law.’ ” United States v. Pohlot, 827 F.2d 889, 896 (3d Cir.1987) (quoting Model Penal Code § 4.01 (1962)). “The language of [18 U.S.C. § 17] leaves no room for a defense that raises ‘any form of legal excuse based upon one’s lack of volitional control’ including ‘a diminished ability or failure to reflect adequately upon the consequences or nature of one’s actions.’ ” United States v. Worrell, 313 F.3d 867, 872 (4th Cir.2002) (quoting United States v. Cameron, 907 F.2d 1051, 1061 (11th Cir.1990)); see also Pohlot, 827 F.2d at 890 (“[T]he defenses that Congress intended to preclude usually permit exoneration or mitigation of an offense because of a defendant’s supposed psychiatric compulsion or inability or failure to engage in normal reflection.... ”).
Effs expert testimony indicates that the true effect of his disorder was not that it rendered him incapable of appreciating the nature and quality or wrongfulness of his actions, but rather that it prevented him from conforming his conduct to the requirements of the law — that is, it created a diminished ability or inability to inhibit inappropriate ' behavior. Dr. Samango-Sprouse testified that executive functioning affects behavior because it provides impulse control and determines a person’s ability to inhibit behavior.9 Additionally, in explaining Effs behavior, she stated that children with executive dysfunction will “repeatedly get into the same problem because they cannot stop the behavior because they so much want what they are going for.” Dr. Boone also testified that people with frontal lobe dysfunction “don’t have the same equipment to control their behavior” as the rest of society and have “no choice” or “less choice” over their behavior. Furthermore, Dr. Boone stated that the tests that Eff scored poorly on measured, in part, the ability to stop an inappropriate behavior. It thus appears that Effs insanity defense is really based on his lack of volition, and Congress specifically precluded this brand of insanity defense.
This is not to say that Effs expert testimony could not have come in to establish that he suffered from a severe mental disease or defect if Eff had other evidence that would allow a rational jury to infer that his condition rendered him unable to appreciate the nature and quality or wrongfulness of his actions. See Dixon, 185 F.3d at 406; United States v. West, 962 F.2d 1243, 1248, 1250 (7th Cir.1992) *720(concluding that the expert testimony supporting the defendant’s claim of a severe mental defect was erroneously excluded because other evidence could establish that the defendant could not understand that his actions were wrong). As the district court noted: “The testimony about Kline-felter causing a severe mental defect might be admissible if there was other evidence to tie that mental defect into an inability (rather than reduced capacity) by Eff to appreciate the wrongfulness of his acts.” Eff, 461 F.Supp.2d at 537. The district court, however, found that Eff “did not present the testimony of these two experts as mere ‘building blocks,’ which would be tied in with other evidence to establish Effs inability to appreciate the nature and quality or wrongfulness of his actions,” and, thus, Effs case “rest[ed] squarely on the experts’ testimony.”10 Id. On appeal, Eff does not challenge this conclusion nor does Eff point to any evidence — besides the testimony of his experts — supporting his insanity defense. Effs expert testimony thus forms the basis of his insanity defense, and, as explained above, such testimony is simply insufficient to warrant a jury instruction.
Given that Effs expert testimony could not support an insanity defense and was offered only to support such a defense,11 such testimony became irrelevant and unhelpful to the trier of fact, and there was no error in its exclusion. Effs claim that the district court’s exclusion of his expert testimony violated his Sixth Amendment right to present a meaningful defense is, therefore, meritless. See Holmes v. South Carolina, 547 U.S. 319, 326, 126 S.Ct. 1727, 164 L.Ed.2d 503 (2006) (“While the Constitution ... prohibits the exclusion of defense evidence under rules that serve no legitimate purpose or that are disproportionate to the ends that they are asserted to promote, well-established rules of evidence permit trial judges to exclude evidence if its probative value is outweighed by certain other factors such as unfair prejudice, confusion of the issues, or potential to mislead the jury.”).
VI.
For the foregoing reasons, the judgment of the district court is AFFIRMED. Accordingly, Appellant’s Motion for Bond Pending Appeal is DENIED.