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: 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: A total of 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. WHAT THIS PAPER ADDS: WHAT IS ALREADY KNOWN ON THE SUBJECT: There is already evidence that some conditions that affect communication, specifically autism, also affect juror perceptions. Research also shows that knowing whether or not a defendant has autism influences how jurors rate defendants. However, autism is not the only condition that is relevant to juror perceptions, as we also know that a high rate of young offenders have language needs, and many have language profiles like DLD. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE: There is little research on how behaviours associated with DLD impact others’ perceptions. This study reports the impact of knowing about a defendant's DLD on juror perceptions, investigating whether knowing about DLD improves judgements on guilt, sentencing lengths, credibility and culpability. Beyond the content of youth offending, this study suggests behaviours associated with DLD lead people to form more negative judgements about youth with DLD. This is important because there is still a lack of awareness of DLD both in‐ and outside the criminal justice system. WHAT ARE THE POTENTIAL OR ACTUAL CLINICAL IMPLICATIONS OF THIS WORK? This study shows that knowing about a person's DLD has largely positive effects on others’ perceptions of them. This implies that recognizing undetected language needs in young offenders, and supporting colleagues and members of the public to know what DLD is and how it affects people, is critical for youth with DLD to be judged fairly. This study will support the case for raising awareness of vulnerability within the youth justice population, and will assist in clinicians evidencing the need for our roles in justice settings.