Signs of autism in babies may present themselves in areas like unusual social engagement, communication, and repetitive behaviors. The deficit in interactive social engagement is the most defining and challenging aspect of autism, which is often one of the early autism signs. The diagnosis is typically made around 3 years based on clinical assessments. Varying levels of verbal communication, echolalia or repetitive speech patterns are among some of the common autism speech patterns exhibited by children. Impaired interpersonal communication, particularly in conversations, is a common feature of autism, requiring explicit learning of social norms by autistic children.
It is not known what causes the neurodevelopmental brain differences in autism. In some cases there seems to be a hereditary influence as having an autistic sibling is a risk factor. Certain genetic conditions are associated with increased risk of being autistic. Infants who experience difficult births, or are born to older parents also have higher risk.
A baby with autism likely will be born physically healthy but she will already have a brain that has developed differently in utero. She may hit developmental milestones on time, but her engagement in social interactions may look different than for babies developing without autism. Eye-contact, smiling, and nonverbal communication (like pointing or gesturing) may be reduced or absent. She may not respond to her name being called. She may not engage in joint attention activities like attending to the pictures as mom reads her a book. She may engage in repetitive behaviors. As her interactive engagement is reduced or absent, she provides little positive reinforcement for parents to continue attempts at communicating. This vicious cycle can further exacerbate the social engagement dysfunction.
And it is this–the deficit in interactive social engagement–that is the most definitional and challenging aspect of autism that can be recognized in children 12-18 months of age or even earlier. A diagnosis of autism is typically made around 3 years of age based on a clinical assessment of symptoms, including reduced social engagement and the presence of restrictive or repetitive behaviors or interests.
Autistic children may or may not develop verbal communication. Those who do may have just a few functional words in their vocabulary, while others may be verbose with extraordinarily large vocabularies–particularly around topics of intense interest. Some autistic children repeat what they hear others say - this is called echolalia - or they may obsessively repeat their own words or phrases. Autistic children may also speak with unusual pitch and rhythm patterns.
The common denominator across the wide range of possible autism presentations is that interpersonal communication is impaired, and nowhere is this more evident than in conversation. Neurotypical children easily learn the social norms around conversations, such as greetings, turn-taking, staying on topic, speaking in a way appropriate for the formality of the situation, and politely bringing the conversation to a close. They subconsciously interpret nonverbal cues, inferring unspoken information to navigate the interaction. Autistic children often must learn these conversational constructs explicitly.
