Sources:
C Allison, S Baron-Cohen, S Wheelwright, T Charman, J Richler, G Pasco, and C Brayne. The Q-CHAT (Quantitative Checklist for Autism in Toddlers): A Normally Distributed Quantitative Measure of Autistic Traits at 18-24 Months of Age: Preliminary Report. J Autism Dev Disord 38(8): 1414-1425 (2008).