Abstract
The objective of this study is to gain new insights into the relationship between clinical signs and age at diagnosis utilizing a new, large, online survey of parents of children diagnosed with ASD. Using multiple statistical approaches, we find that clinical signs and symptoms that most strongly predict early diagnosis are not necessarily specific to autism, but rather those that initiate the process that eventually leads to an ASD diagnosis. Given the high correlations between symptoms, only a few symptoms are found to be important in predicting early diagnosis. Even though our data are drawn from parents' retrospective accounts, we provide evidence that parental recall bias and/or hindsight bias did not play a significant role in shaping our results.