Doctor of Philosophy (PhD)



Document Type



Many researchers have cited the continuing increase in the prevalence of autism worldwide and have speculated on the potential causes of that increase. One theory that suggests at least a contributory effect is the general trend for parents to have children at later ages. Previous research has begun to examine the relationship between advanced parental age at conception and the incidence of autism and have noted strong relationships between advanced parental age and other developmental disabilities. The purpose of this study was to not only confirm the relationship between advanced parental age and autism risk but to extend that knowledge to the association between parental age and severity of autism symptoms as well as comorbid psychopathology. The current study included 252 participants between the ages of 2-17 years of age and their parents. It was found that paternal age and child’s gender were both significant predictors of an autism diagnosis in this clinical sample. Males were found to have an odds ratio of 4.17 (95% Confidence Interval, 2.06-8.44) when compared to females. While the effect was not as large for paternal age, the predictive power was found to be statistically significant (odds ratio = 1.06; 95% Confidence Interval, 1.00-1.12). Child’s gender and paternal age were also found to be significant predictors of autism severity; however, paternal age was not found to be a significant predictor of comorbid symptoms. Interestingly, maternal age was not found to be a significant predictor of autism risk, severity, or comorbid psychopathology in this sample. Possible explanations for this finding and other findings are discussed, as well as future directions for research in this area.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Matson, Johnny



Included in

Psychology Commons