Are Moral and Socio-conventional Knowledge Impaired in Severe Traumatic Brain Injury?

Objective: The aim of this study was to investigate explicit moral and socio-conventional knowledge in Traumatic Brain Injury (TBI) patients. Method: A group of 28 TBI patients was tested on a new set of moral and socio-conventional items. Responses of TBI patients were compared with those of 28 matched controls. Participants had to report how hard would be to perform specific moral or socio-conventional transgressions, using a 10-point Likert scale. We analyzed our data through mixed-effects models, to jointly assess by-participants and by-items variance. The factors considered were Type of Item (Moral vs. Socio-conventional) and Group (TBI vs. Controls). Results: Results revealed a significant interaction between Type of Item and Group (χ2[1] = 25.5, p < .001). Simple-effects analyses showed that TBI, as Controls, were able to differentiate moral and socio-conventional transgressions (χ2[1] = 72.3, p < .001), as they deemed the former as more difficult to enact. TBI patients, however, evaluated moral transgressions as easier to fulfill (χ2[1] = 12.2, p = .001). Conclusions: TBI patients can clearly differentiate moral and socio-conventional transgressions, suggesting that the explicit knowledge of these two dimensions is spared. TBI patients, however, considered moral transgressions as easier to fulfill with respect to Controls. This finding may suggest a tendency in TBI patients to underestimate the weight of moral transgressions.