Investigating the structure of the autism-spectrum quotient using Mokken scaling.

Abstract

Traits similar to those shown in autism spectrum condition (ASC) are apparent in relatives of individuals with ASC, and in the general population without necessarily meeting diagnostic criteria for an ASC. We assess whether the Autism-Spectrum Quotient (AQ), a self-report measure, has hierarchical properties using Mokken scaling. Hierarchical scales allow the presence of a latent trait to be identified by discovering whether and how many specific items form an ordered array along it. Data were collected from 2 groups: (1) people with ASC (n = 449: 240 males, 209 females, M(age) 35.4 years, SD = 12.8) and (2) university students (n = 943: 465 males, 475 females, M(age) = 23.0 years, SD = 8.4). A single Mokken scale was obtained in the data from university students and 3 scales were obtained in the data from people with ASC. The scales all showed moderate Mokken scaling properties with the single scale obtained from university students showing weak invariant item ordering and 2 of the scales from people with ASC showing weak invariant item ordering. The AQ formed reliable Mokken scales. There was a large overlap between the scale from the university student sample and the sample with ASC, with the first scale, relating to social interaction, being almost identical. The present study confirms the utility of the AQ as a single instrument that can dimensionalize autistic traits in both university student and clinical samples of ASC, and confirms that items of the AQ are consistently ordered relative to one another.

Is the Autism-Spectrum Quotient a Valid Measure of Traits Associated with the Autism Spectrum? A Rasch Validation in Adults with and Without Autism Spectrum Disorders

“…This result is in line with previous research using factor analysis (Austin 2005; Hoekstra et al 2008; Hurst et al 2007; Stewart and Austin 2009) and Mokken scaling (Stewart et al 2015). The hypothesized single latent variable is not consistent with the multidimensional nature of ASD, as expressed in the Diagnostic and Statistical Manual of Mental Disorders, DSM-5 (American Psychiatric Association 2013), or with the fact that Barron-Cohen (2001a) selected the AQ items from the domains in the “triad” of autistic symptoms.…”

“…Intriguingly, nine of these items (11, 13, 17, 22, 26, 34, 38, 44, and 47) are among the ten items that passed the Mokken scaling test on people with ASD (Stewart et al 2015). Hoekstra et al (2008), using CFA, found that the AQ consisted of two second-order factors, one of them including Social skill, Attention switching and Communication .…”

Empathy and face processing in adults with and without autism spectrum disorder

“…The AQ is a 50‐item self‐report measure that can dimensionalize behavioral traits typical of ASD in both university student and clinical samples [Baron‐Cohen et al, ; Stewart et al, ]. There are ten items devoted to each of five core domains: (a) social skills, (b) communication skills, (c) imagination, (d) attention to detail, and (e) attention switching/tolerance of change.…”

A Psychometric Evaluation of the DSM-IV Criteria for Antisocial Personality Disorder: Dimensionality, Local Reliability, and Differential Item Functioning Across Gender

“…In recent years, MSA has increased in popularity in the fields of psychological and health assessment (e.g., Chou, Lee, Liu, & Hung, 2017; Lenferink et al, 2016; Murray, McKenzie, Murray, & Richelieu, 2014; Stewart, Allison, Baron-Cohen, & Watson, 2015; van den Berg, Paap, & Derks, 2013; Watson et al, 2012). MSA identifies scales that allow an ordering of individuals on an underlying scale using unweighted sum scores.…”