Date created: | Last Updated:

Category: Project

Description: In this simulation study, we investigated three different types of response bias in trauma reports, such as overreporting, rarely investigated underreporting, and, exceptionally neglected type - strategic faking. Undergraduate students (N = 151) were pre-screened for PTSD-related symptoms, and then randomly allocated to one of four conditions: control group (n = 40), fake bad (n = 37), fake good (n = 36), or to mixed faking (n = 38). Members of the control group were told to honestly respond to our questionnaires, whereas the simulation groups received vignettes depicting situations they should relate to (i.e, seeking academic extension, getting a job in a trauma center). All participants received the PTSD checklist (PCL-5), Supernormality scale which screens for symptom denial, and a measure of overreporting, Inventory of Problems-29 (IOP-29). First, our results showed that approximately 20% of honest participant indicated severe PTSD symptomatology, and that that 10% of students also engage in symptom denial, which warrants attention. Further, the effect of group was significant for all three measures (Fs(3, 147) > 13.78, ps <. 001, ɳ² > .22), with faking bad group exhibiting the most severe symptom presentation, faking good the least severe one, while the mixed faking group almost perfectly imitated the results of the control group on all measures. Thus, it appears that instructing an individual to strategically exhibit both overreporting and underreporting results in the most balanced symptom presentation, indistinguishable from genuine ones. As this is the first study to combine stand-alone symptom validity tests of both positive and negative response bias, further investigation is necessary.