Special Interests in Adults with and without ASD: A Comparison Study

Background:  Although restricted interests have been included as a diagnostic symptom of ASD since the disorder’s original inclusion in the DSM, only a handful of studies have been conducted on the topic, with most focusing on the content of interests. This study investigated the quantitative components of interests.

Objectives:  The goal of this study was to determine whether there were differences between adults with ASD and those without ASD who have special interests. Both groups had similar interest content in areas such as computer/video gaming, animals, sports, and anime/Japanese culture.

Methods:  Twenty adults without ASD who were recruited for having a special interest (TD-SI group) which they self-identified being "obsessed" with, and eighteen adults with high-functioning ASD (ASD group) confirmed with the ADOS, reported on aspects of their interest including when it started, the duration, when it peaked, the percentage of time they do spend on their interests, the percentage of time they would liketo spend on their interest, the amount of money they spend on their interest, and the number of people they share their interest with. Full scale IQ (FSIQ) was calculated based on the Wechsler Abbreviated Scale of Intelligence (WASI-II), and the Autism Spectrum Quotient (AQ) was used to obtain an estimate of ASD symptoms.

Results:  A one-way ANOVA was used to test for differences between the ASD and TD-SI groups on the variables measured. There were no significant differences between the groups on age, and both groups had FSIQs in the average range. There was a significant difference in AQ scores (TD-SI x=17; ASD x=27), indicating the TD-SI group did not have high levels of ASD symptoms. On the interest variables measured, there were no significant differences between the groups for the age their interest started (x=10.5 years old for both groups), the duration of their interest (TD-SI x= 14 years; ASD x= 13 years), age their interest peaked (TD-SI x=17; ASD x=16), percentage of their spare time they do or would like to spend on their interest; (x~ 50% for both groups on both measures), or the amount of money they spend on their interest (TD-SI x=$52/month; ASD x=$54/month). Although not yet statistically significant (data collection is ongoing and p is approaching significance) the groups did differ on the number of people they shared their interest with (TD-SI x=13 people; ASD x= 6 people).

Conclusions:  The results indicate that interests in ASD are not atypical on the variables measured compared to those of TD peers who also have special interests except that they are less likely to share their interest with others. This may reflect that having better social skills allows you to be more social when pursuing your interest or that involving more people in your interest creates better social skills and/or opportunities. Further study is warranted to investigate the social components of interests and their impact on people with ASD.