Date of Submission


Degree Type


Degree Name

Doctor of Psychology (PsyD)



Department Chair

Robert A DiTomasso, PhD, ABPP

First Advisor

Stephen Poteau, PhD

Second Advisor

Robert A DiTomasso, PhD, ABPP

Third Advisor

Michael Roberts, PsyD

Fourth Advisor

Stephanie Felgoise, PhD, ABPP


The purpose of this study was to further examine the Dunning-Kruger effect as it relates to knowledge of autism, source of information, and endorsement of vaccination policy. Specifically, the study assessed the relationship between confidence in autism awareness and the belief that vaccines cause autism. It also examined the relationship between the source of information regarding autism and vaccines and vaccination attitudes. Last, it assessed whether individuals with higher confidence levels in the internet would be more likely to have both anti-vaccination attitudes and lower awareness of autism facts. Adult participants (N = 199) were surveyed on various social media outlets using five self-report measures. First, it was predicted that anti-vaccination individuals would show higher confidence in their knowledge and lower knowledge of autism compared to pro-vaccination individuals. Second, it was predicted that anti-vaccination individuals would be more likely to rely on the internet than physicians compared to pro-vaccination individuals. Last, it was hypothesized that vaccination stance would differ on confidence in source between physician and internet. The findings confirmed that anti-vaccination individuals were more confident in their knowledge of autism and vaccines compared to pro-vaccination individuals. Further, pro-vaccination individuals were shown to be more likely to obtain information from physicians whereas source was equally distributed between internet and physician for anti-vaccination individuals. Last, those pro-vaccination individuals displayed higher levels of confidence in the internet overall and lower levels of confidence in physicians compared to anti-vaccination individuals in whom the opposite pattern was found. Implications are further discussed.