The Use of Internal State Terms by Individuals with Autism Spectrum Disorders: A Scoping Review

Internal state terms (ISTs) include words describing emotions, thoughts, volitions, obligations, desires, and perceptions. This scoping review aimed to map and synthesize evidence regarding the production of ISTs in individuals with Autism Spectrum Disorder (ASD) without intellectual disability and to investigate the effects of age, gender, Theory of Mind (ToM) skills, and elicitation tasks on their production. A literature search was conducted manually and electronically in Scopus, ScienceDirect, ERIC, and PubMed, identifying 29 peer-reviewed empirical studies published between 2006 and 2025. Findings were heterogeneous. Some studies reported lower IST production in individuals with ASD compared to neurotypical controls, whereas others found differences only in specific IST categories, mainly cognition and emotion terms, or reported no significant group differences. Findings regarding gender, ToM skills, and elicitation tasks were mixed. In both groups, older participants produced more ISTs than younger participants; however, developmental trajectories suggested that emotion and cognition terms were particularly challenging for individuals with ASD, who required more time to acquire them than their typically developing (TD) peers. Furthermore, TD participants produced significantly more ISTs when narrating people’s everyday interactions, whereas communication context did not appear to influence IST production in individuals with ASD. Research examining IST production in preschoolers and adults with ASD remains limited, and little is known about the developmental trajectories of ISTs in this population.