ciences and Education at the University of Perugia reviewed and approved this study. The parents provided their written informed consent to participate in this study for themselves and on behalf of the children enrolled in our study. The study presented “no more than minimal risk.” In order to replicate Evans’  procedure, the children were divided into two age groups: 6–8 years old (N = 38) and 9–11 years (N = 38).
Materials and procedure
Four questionnaires were administered to both the children and the parents. The questionnaires maintained the same format as the questionnaires that Evans  used, i.e., item number, item type (open or closed questions), Likert scale ranges, and open-ended questionnaire coding system. However, the item content, instructions, and questionnaire stimuli were modified (see S2 File–Details of Measure for a detailed description of the measures, coding, and procedures). The open questions were created to collect uncensored personal explanations of disability and diversity, whereas the closed questions were designed to elicit a response of agreement, presented in a forced–choice model, using explanations built on the basis of the three disability models. The latter techniques act as scaffolds , reminding respondents of the explanations according to the publicly present disability models, of which they may not have access to without such support.
The children were interviewed at their home separately from their parents. Comprehension of the concept of “disabled vs. normal person” was verified via a semantic discrimination task. The children’s explanation of disability (Disability Explanation) was assessed using one open-ended and one closed-ended questionnaire, while activities or interests (Child’s Interests and Activities), as well as agreement with health and disability statements (Child’s Disability Knowledge), were assessed using two closed-ended questionnaires (S2 File Details of Measures). Statements on health and disability were constructed on the basis of false beliefs (stereotypes) and true content (knowledge).
After checking the child’s questionnaires, one child’s parent completed three closed-ended and one open-ended self-administered questionnaire. The open-ended questionnaire and one of the closed-ended questionnaires were based how they as parents explained the concept of disability to their child (Disability explanation). Child activities or interests that the parent encouraged (Parent’s interests and activities encouraged) and how they explained diversity to their child (Parent’s education about diversity) were assessed using two closed-ended questionnaires (S2 File–Details of Measure).
Disability Explanation—Open-Ended Questionnaire
For the present article, in order to force data in the room of a scientific article, we decided to report the only quantitative data, reserving a qualitative analysis for a future article. The disability model frequency scores were analyzed in a 3 (disability model: individual, social, biopsychosocial) x 3 (age group: children 6–8 years, children 9–11 years, parents) mixed-design analysis of variance (ANOVA). Results are shown in Fig 1. The analysis revealed a main effect for disability model, F(2, 148) = 402.257, p < 0.01, and a significant interaction, disability model x age group, F(4, 296) = 15.678, p < 0.01. Three univariate ANOVAs clarified the nature of the interaction by demonstrating a significant effect of age for the individual, F(2, 149) = 27.212, p < 0.01, and the social model, F(2, 149) = 27.146, p < 0.01. Fisher’s post-hoc LSD showed that children were more likely to use the individual model (p < 0.01) while parents were more likely to use the social model (p < 0.01).
Disability Explanation—Closed-Ended Questionnaire
The disability model agreement scores were analyzed in a 3 (disability model: individual, social, biopsychosocial) x 3 (age group: children 6–8 years, children 9–11 years, parents) mixed-design analysis of variance (ANOVA). Results are reported in Fig 2. A main effect for disability models emerged F(2, 147) = 78.828, p < 0.