- By the time most babies reach the age of six months, they will likely turn their heads toward sounds and familiar voices. Babies with autism may fail to respond to such noise stimulus and they may also neglect to make sounds or smile in response to a parent's cooing or talking.
- At nine months of age, many babies will smile, laugh or show excitement for baby games like peek-a-boo or patty-cake. An autistic baby, however, may not be interested in human attention and he may show little or no interest in activities that take place around him.
- Babies with autism may fail to bond with their parents, siblings or other caregivers and they may not look toward an adult for comfort or reassurance when they become upset. They may respond to their parents in the same manner they respond to strangers.
- The lack of babbling and gesturing may be a sign of autism in babies who reach their first birthday. For most infants, this is a time of rapid development and interaction with their expanding world, but autistic babies may not perform typical milestones, such as waving goodbye or pointing toward something they want, like a cookie (see Resources).
- An autistic baby may stiffen when a parent attempts to cuddle him and he may not maintain eye contact. According to MayoClinic.com, autistic babies may be more content by themselves than around others.
- Autistic babies may not pay attention to popular play items, such as dolls, balls or stuffed animals. However, they may perform repetitive actions, such as rotating their hands, turning the pages of a book or lining up blocks.
