Autism affects a child's brain, impacting her development and interaction with other people. While the National Institute of Mental Health (NIMH) states that autism symptoms fully present themselves by age 3, a regression of normal behavior can start as early as 6 months. AutismSpeaks.org says that the earliest symptoms of autism are an absence of normal infant behavior, such as babbling and gesturing. These early signs should not be ignored---treating autism as soon as possible can help minimize the effects.
Warning Signs in Infancy
Helpguide.org states that certain behaviors expected in developing children are absent in autistic children. At 6 months of age, the autistic infant may not smile or show happiness with facial expressions. By 9 months, happy expressions and sounds, such as laughing, are still absent; in addition, the baby does not reciprocate the smiles and laughter of others. When the child is 1-year-old, he will not respond with gestures, such as waving, nor will he babble or use other verbal responses. By 16 months, the child will not be using formed words, unlike his non-autistic counterparts.
Additional Behavioral Symptoms
The NIMH states that an autistic baby has problems responding to others, and might seem to be in her own world. Helpguide.org notes that the autistic infant will not make eye contact with people or visually follow a moving object. A lack of gesturing is also an autism warning sign in young babies. The autistic baby will not make hand movements to get attention, nor imitate another person, such as a parent.
Additional Verbal Symptoms
Helpguide.org states that one symptom common in autistic babies, lack of verbalization, is often misconstrued as the child being a "good baby." The child will be quiet and not make any noises, such as crying.
