"How can you tell if a child has ASD Level-1 (high-functioning autism)? And should we take him to a specialist to have him formally diagnosed?" I'll answer the second question first: Yes, if you suspect High-Functioning Autism (HFA), then by all means seek a diagnosis so you will know for sure. It's better to know than not to know. If your child has the disorder and doesn’t know, it affects him anyway. If he does know, he can minimize the negative impact - and leverage the positive. Without the knowledge that you have it, you will often fill that void with other, more damaging explanations (e.g., I'm a failure, weird, a disappointment, not living up to my potential , etc.). Here are some of the traits of High-Functioning Autism and Asperger's. If these characterize your son, then strongly consider consulting a professional: 1. Cognitive Issues-- Mindblindness, or the inability to make inferences about what another person is thinking, is a core issu...