The first red flags of autism in infants often appear within the first year of life and can be subtle, involving social, communication, sensory, and behavioral differences. One of the earliest and most noticeable signs is **lack of or limited eye contact**. While typical infants begin to make eye contact with caregivers by around 2 months and engage in social smiling by 6 months, infants who may be autistic often avoid looking directly at faces or fail to sustain eye contact during interactions. This lack of eye contact can signal difficulties in social engagement and connection.
Another early red flag is **limited or absent social smiling and responsiveness**. Most babies start to smile socially by 6 months, responding to caregivers’ smiles and voices. Infants at risk for autism may show little interest in social games like peek-a-boo, may not smile back, or may seem disengaged when others try to interact with them. They might also show **reduced or absent response to their name** being called, which is a key early indicator of social and communication challenges.
Communication delays are also important early signs. Infants typically begin babbling and making a variety of sounds by 6 to 9 months, but babies with autism may show **delayed or limited babbling**, fewer vocalizations, or unusual vocal patterns that do not synchronize with caregiver speech. They might also show fewer gestures such as pointing, waving, or reaching to communicate needs or share interest, which are important milestones in early communication development.
Sensory processing differences often emerge early as well. Some infants may be **overly sensitive to sounds, lights, or textures**, reacting with distress to everyday stimuli like loud noises or certain fabrics. Others may appear **under-responsive**, showing little reaction to sensory input that typically draws attention, such as loud sounds or bright lights. These sensory differences can affect how infants engage with their environment and caregivers.
Repetitive behaviors or unusual motor patterns can also be early signs. Infants might exhibit **repetitive movements** such as hand-flapping, rocking, or stiff arm postures. These behaviors are often ways to self-soothe or manage sensory input and may be noticeable even before the child is walking or talking.
Other behavioral red flags include **difficulty adapting to changes** in routine or environment, frequent irritability, excessive crying, or trouble calming down. These temperament traits can be early indicators of challenges with regulation and adaptability often seen in autism.
In summary, the earliest red flags of autism in infants include:
– **Limited or no eye contact** and social smiling
– **Reduced response to name** and social engagement
– **Delayed or atypical babbling and gestures**
– **Unusual sensory responses** (either heightened or diminished)
– **Repetitive body movements** or motor patterns
– **Difficulty with calming, irritability, and adapting to change**
Recognizing these signs as early as 6 to 12 months can prompt timely evaluation and intervention, which are crucial for supporting the child’s development and improving long-term outcomes. Parents and caregivers noticing these behaviors should consult healthcare professionals for developmental screening and guidance.
