Investigating autistic traits, sensory experiences and personality: a mixed methods approach

Investigating autistic traits, sensory experiences and personality: a mixed methods approach

The relatively recent spectrum view of Autism Spectrum Disorder (ASD) with symptoms potentially varying from mild to severe, in combination with high rates of co-morbid conditions, has raised the issue of heterogeneity among individuals with ASD. This has consequent challenges for obtaining consistent research findings and for the diagnosis of those with less severe symptoms or high-functioning ASD. Since evidence has suggested the presence of non-clinical levels of autistic traits within the general population, this thesis aimed to explore these traits in relation to personality and sensory experiences via a mixed methods design, comprising two parts. Part I consisted of two studies aimed at exploring the lived experiences of individuals with ASD and their caregivers, in relation to sensory experiences, in order to inform the subsequent studies. The focus of Part II was to explore autistic traits in the broader population and consisted of three studies.

In Part I, Study one comprised a systematic review of studies containing qualitative data from caregivers of individuals with ASD in relation to sensory experiences. Key sensory challenges reported related to: single senses (most commonly touch, taste, movement, and hearing), sensory issues embedded in certain situations, understanding the individual's sensory experiences, strategies to manage sensory issues, and the impacts of an individual’s sensory issues on the family. A discrepancy between caregiver reports of the benefits of sensory based interventions and existing empirical evidence was identified. Study two involved qualitative analyses of sensory experiences, as described by three individuals with a diagnosis of ASD. Three main themes were identified: dominant types of sensory experiences including visual experiences, sounds, tastes and food preferences, tactile experiences, and less dominant senses including smells and movement, and multi-sensory experiences; management of sensory challenges; and participants’ perceptions of change and difference.

The first study of Part II, study three, investigated the psychometric properties of the short form of the Autism Quotient (AQ-10) based on two separate non-clinical samples (N1 = 194; N2 = 310), via exploratory and confirmatory factor analyses. Results indicated a 7-item 3-factor solution for the AQ-10, with factors labelled social cues, intentions, and multi-tasking. Since the social cues factor accounted for the largest amount of variance (31%), and other factors together accounted for minimal explained variance (27%), only items comprising social cues were selected as a measure of autistic traits for subsequent analysis and studies. Structural equation modelling was conducted to analyse co-variate paths between social cues and selected personality traits, with findings indicating that social cue reading was not related to trait anger, introversion, or collecting. These results, therefore, challenged stereotypical associations between these constructs and ASD, and were consistent with existing evidence that social aspects of autistic traits are independent from repetitive behaviours, such as collecting. Study four extended these findings through exploration of social cue reading in relation to trait flexibility, anxiety, and sensory experiences. Consistent findings indicated positive associations between inflexibility, anxiety, and auditory and visual hypersensitivity, potentially suggesting that individuals with higher trait inflexibility and anxiety could experience greater sensory sensitivity or vice versa. Finally, study five involved a qualitative analysis of accounts of sensory experiences from a large combined sample (N = 504) of individuals from the general population. Content analysis of responses resulted in six main categories. Similar percentages of individuals scoring low and high on autistic traits (based on social cue reading difficulty) reported challenges relating to single senses (visual, auditory, tactile, and olfactory), people and crowds, and unexpected or unfamiliar stimuli. Unexpectedly, more individuals with low levels of autistic traits reported specific fears and anxiety responses to sensory stimuli, raising questions as to whether those with poorer social cue reading ability are more prone to report generalised anxiety (in line with trait anxiety) or are less aware or avoid reporting responses to sensory stimuli. Overall, the role of trait flexibility is highlighted across Parts I and II as being a central feature in individuals reporting experiences of sensory sensitivities. The collective findings of this program of research have implications for the further development of both clinical interventions and theoretical understandings, in addition to accommodations for individuals with sensory sensitivities and ASD traits. Keywords: autism, autistic traits, ASD, social cues, sensory, inflexibility, trait anger, trait anxiety, collecting interests.