The impact of Developmental Language Disorder in a defendant’s description on mock jurors’ perceptions and judgements

Background: While it has been posited that young people with language needs may be viewed more negatively (e.g. as more rude, less cooperative) than those without language needs, the impact of knowing about a person’s language needs on others’ perceptions has yet to experimentally tested. Aims: This study sought to examine whether the presence of a Developmental Language Disorder (DLD) diagnosis in a defendant’s information would affect mock juror ratings of guilt, sentence length, credibility and blameworthiness. Methods & Procedures: 143 jury eligible participants read a vignette of a non-violent crime. Half of the participants (N= 73) were told the defendant has a diagnosis of DLD, while half (N= 70) were not told. Outcomes & Results: Preregistered analyses found that DLD information affected ratings of credibility and blameworthiness, though not judgements of guilt or sentence length. Unregistered content analyses were applied to the justifications participants gave for their ratings: these suggested that participants who did not have the DLD information judged the defendant more on his personality and attitude, and drew more links to his (perceived) background, while participants who received the DLD information condition made more reference to him having cognitive problems. Conclusions & implications: Unlike in previous studies of the impact of autism information, information about a defendant’s DLD did not affect mock jurors’ likelihood of finding them guilty, or lead participants to give longer sentences. However, our findings suggest knowing a person has DLD does affect others’ perceptions of credibility and blameworthiness.