Five Factor Personality and Adults with Autism

Background: Adults with autism, regardless of level of functioning, demonstrate generally poor prognoses. Research suggests studying the personalities of individuals with autism could give better insight into the heterogeneity that exists within the autism phenotype (Eaves et al., 1994; Hepburn & Stone, 2006; Ozonoff et al., 2005; Schwartz et al., 2009; Wing, 1997). Based on extensive research from a variety of cultures and age groups, there is a well-established consensus among personality researchers that the Five Factor Model of Personality ("The Big 5") provides a robust account of the dimensions of human personality variation and behavior. To date, very little is known about the personality traits associated with Autism Spectrum Disorders, and even less is known regarding how individuals with autism present in terms of the Five Factor Model of Personality specifically (Ozonoff et al., 2005, De Pauw et al., 2011).

Objectives: (1) To determine the extent to which The Big 5 and its facets account for variability in Autism Spectrum Disorder (ASD) symptomatology in adults with and without diagnoses of ASD (2) To verify differences in personalities of adults with and without ASD at both the factor and facet-levels and (3) to empirically identify distinct behavioral phenotypes that exist within ASD in terms of Big 5 factors and facet-level variability.

Methods: A sample of 821 adults (359 with ASD; 462 without) completed an online survey consisting of the Ritvo Autism Asperger’s Diagnostic Scale Revised (RAADS-R; Ritvo et al., 2010), the International Personality Item Pool Representation of the NEO-PI-R (IPIP-NEO-120; http://ipip.ori.org), and demographic information. The RAADS-R is an 80-item self-rated diagnostic scale for measuring autism based on the DSM-IV and ICD-10 diagnostic criteria. The IPIP-NEO-120 is an online, public domain tool for personality measurement which reports the individual level of personality under each of the five domains in the Five-Factor Model.

Results: IPIP-NEO-120 scores accounted for 71% of the variance in RAADS-R scores. Neuroticism was found to be positively correlated with RAADS-R scores, while Extraversion, Openness to experience, Agreeableness, and Conscientiousness were found to be negatively correlated with RAADS-R scores. Based on k-means Cluster Analysis, four distinct Big 5 personality subtypes emerged within adults with ASD.

Conclusions: Information gained from this study further emphasizes the “spectrum” nature of autism, in that an autism diagnosis consists of a variety of behaviors and symptoms that manifest differently from person to person. Results indicated that while the personalities of adults with and without autism significantly differed as expected, personality differences also emerged within the group of adults with autism. These findings provide direction for future intervention, by describing individuals on the autism spectrum based on a continuum of combinations of personality factors, a true spectrum, as opposed to characterizing these individuals solely based on being “low” or “high” functioning.