The Relationship of Age with the Autism-Spectrum Quotient Scale in a Large Sample of Adults

Abstract

Background: The historical focus on autism as a childhood disorder means that evidence regarding autism in adulthood lags significantly behind research in other age groups. Emerging studies on the relationship of age with autism characteristics do not target older adult samples, which presents a barrier to studying the important variability that exists in life span developmental research. This study aims to further our understanding of the relationship between the Autism-Spectrum Quotient Scale and age in a large adult sample. Methods: The present study examines the relationship of Autism-Spectrum Quotient Scale (AQ) scores with age in 1139 adults, ages 18-97 years. Participants came from three distinct samples-a sample of primarily students, a sample of MTurk participants, and a sample of primarily community dwelling older adults. The majority of the participants did not self-report an autism diagnosis (91%), were female (67%), and identified as White (81%). Participants completed the AQ primarily via online surveys. Researchers scored the AQ following six common scoring practices. Results: Results of preregistered analyses indicate that autism characteristics measured by the AQ are not strongly associated with age (r values from -0.01 to -0.11). Further findings indicate that the measurement of autism characteristics is consistent across age into late life using both multiple groups and local structural equation modeling approaches to measurement invariance (comparative fit indices = 0.82-0.83, root mean square error = 0.06) as well as reliability analysis. Finally, demographic and autism-related variables (sex, race, self-identified autism spectrum disorder diagnosis, and degree of autism characteristics) did not moderate the relationship between age and autism characteristics. Conclusion: These results suggest that self-reports of autism characteristics using the AQ do not vary strongly by age in this large age-representative sample. Findings suggest that the AQ can potentially serve as a useful tool for future research on autism across the life span. Important limitations on what we can learn from these findings point toward critical avenues for future research in this area.

Exploring relationships between autistic traits and body temperature, circadian rhythms, and age

“…We consider that the significant negative relationship for AQ is small but valid and worth discussing, whereas the other relationships that show very small relations are not. This result is consistent with a previous finding in the United States 31 . While mixed evidence has been reported for changes in ASD-like characteristics with aging in people with clinical ASD diagnosis 41 , 42 , our findings suggest that autistic traits could be mitigated with aging in the general population.…”

“…As for a possible relationship between autistic traits and body temperature, we predicted that people with greater autistic traits, that is, higher AQ and SQ scores and lower EQ scores, would have lower body temperatures based on the evidence for the longitudinal shifts in clinical ASD diagnosis 7 and body temperatures 16 . We also expected that negative relationships 31 between autistic traits and age. We did not have any hypotheses regarding the relationship between autistic traits and circadian rhythms.…”

“…Thus, we explored the relationship between autistic traits and circadian rhythm. Regarding the relationship between autistic traits and age, a study performed in the United States reported that there existed a negative relationship between AQ scores and age 31 . We explored the relationships between age and AQ, EQ, and SQ scores in the Japanese population.…”

Age differences in broader autism phenotype traits from young adulthood to older adulthood

“…The use of a continuous, self-report subclinical measure of BAP-related traits is useful in this regard-it can capture a broader range of variation in BAP-related traits among individuals who are higher in autistic traits but nevertheless do not have a formal ASD diagnosis. However, the selection problem of older adults being historically excluded from this research is compounded by the fact that there are cognitive and language limitations that might prevent individuals from being able to accurately report on their own BAP traits (Hand et al, 2020;Lodi-Smith et al, 2021). In fact, executive and cognitive functioning deficits are some of the correlates of the BAP among older adults (Stewart et al, 2018(Stewart et al, , 2020Wallace et al, 2016).…”

Atypically slow processing of faces and non-faces in older autistic adults

“…Based on the relatively low AQ and ADOS scores and the adulthood diagnoses, some may argue that our sample only represents autistic individuals with relatively mild challenges, for example, see also prior discussions on this topic ( Koolschijn et al, 2017 ). While autistic traits as measured with the AQ do not seem to correlate with age ( Lodi-Smith et al, 2021 ), the psychometric properties of AQ and ADOS in older adults have been questioned ( Baghdadli et al, 2017 ; Bastiaansen et al, 2011 ). Nevertheless, our mean AQ scores match those from other ASD studies ( Blomqvist et al, 2014 ; Kirkovski et al, 2015 ; Mueller et al, 2013 ; Ring et al, 2020 ; Roine et al, 2013 ; Ruzich et al, 2015 ; Yasuda et al, 2014 ).…”