Autism spectrum features

Autism spectrum disorder (ASD) rests on two core domains — and if you can name both, you can recognize the presentation at any age. Think of it as a "2 + 2": two symptom domains, both required, present from early development.

Domain 1 — persistent deficits in social communication and social interaction. This includes trouble with social-emotional reciprocity (back-and-forth conversation, sharing interests/emotions), deficits in nonverbal communication (reduced eye contact, limited gestures and facial expression), and difficulty developing, maintaining, and understanding relationships.

Domain 2 — restricted, repetitive patterns of behavior, interests, or activities. Learn the classic four: stereotyped/repetitive movements or speech (hand-flapping, lining up toys, echolalia), insistence on sameness and inflexible routines (distress at change), highly restricted, fixated interests of abnormal intensity, and hyper- or hypo-reactivity to sensory input (indifference to pain, aversion to sounds/textures).

Recognition across ages: In toddlers/young children, watch for delayed or absent language, not responding to name, limited eye contact, lack of pointing/showing, minimal pretend play, and repetitive movements. In school-age children, difficulty with peers, missing social cues, literal/rigid thinking, and intense narrow interests. In adolescents/adults — especially those who "mask" — features can be subtler: social awkwardness, difficulty with unwritten social rules, need for routine, and deep focused interests. It's a spectrum: severity and language/intellectual ability vary widely, and symptoms are present in early development even if not fully recognized until social demands rise.

Clinical Pearl: Recognize ASD by the two required domains: (1) social-communication deficits AND (2) restricted/repetitive behaviors and interests, present from early development. Both must be present — social difficulty alone isn't autism without the restricted/repetitive-behavior piece.