Which condition is characterized by abnormal social interaction and the use of language for social communication before age 3?

The condition characterized by abnormal social interaction and challenges in using language for social communication before the age of 3 is autism. Autism Spectrum Disorder (ASD) is known for its early onset and distinctive features, including difficulties in social communication and interaction. Infants and toddlers with autism may exhibit limited eye contact, lack of connection in social exchanges, and may struggle to engage in typical back-and-forth conversations.

Additionally, they might display repetitive behaviors or have restricted interests, but the key indicators in the context of this question are the issues with social interaction and language use at a very young age. Early identification and intervention are crucial in managing autism, as these can significantly improve outcomes for affected individuals.

Asperger disorder, which is now considered part of the broader autism spectrum, often presents with less severe social impairments and typically involves higher verbal skills, which might not align with the described early communication challenges. Attention deficit hyperactivity disorder (ADHD) primarily involves difficulties with attention, hyperactivity, and impulsivity, lacking the key traits of social interaction deficits described. Learning disabilities usually refer to specific difficulties in acquiring skills related to reading, writing, or arithmetic, rather than the overall social communication deficits seen in autism.