The (Small) World of Validity Test Research According to Leonhard and Leonhard (2024): A Critique

The paper “Neuropsychological malingering determination: The illusion of scientific lie detection” by Chunlin Leonhard and Christoph Leonhard (2024) critically assesses the use of symptom and performance validity tests (SVTs/PVTs) in forensic settings. The authors argue that the research community’s lack of critical examination leads to a flawed peer review process and scientifically dubious SVTs/PVTs, making them unsuitable for expert testimony. We comment on the arguments presented by Leonhard and Leonhard, questioning the scientific rigor of their approach, the limited scope of their literature review, their mischaracterization of validity tests as “malingering tests,” and their naive reliance on medical standards for evaluating SVTs/PVTs. We assert that referring to validity tests as “malingering tests” is a straw-man argument, as SVTs/PVTs are designed not to detect malingering per se, but to identify symptom overreporting or cognitive underperformance, respectively. In contrast to Leonhard and Leonhard’s stance on the inadmissibility of validity tests, other researchers offer a more balanced perspective, indicating that SVTs/PVTs, despite their limitations, receive favorable reviews and general acceptance in the field. In conclusion, we find Leonhard and Leonhard’s analysis unconvincing and argue that their questionable arguments undermine the credibility of symptom and performance validity research. The potential consequences of this include diminished funding prospects. We emphasize that SVTs/PVTs provide valuable insights into symptom overreporting and cognitive underperformance, which are crucial for accurate diagnosis and treatment.