Social communication is important for success at home, school, work, and in the community. Lacking the ability to effectively process and convey information to others can lead to deficits in maintaining personal relationships and academic failure in school. Deficits in social communication skills can include a broad array of verbal and nonverbal behaviors important for reciprocal social interaction. In this dissertation, we are interested in how children use and integrate verbal and multiple channels of non-verbal behaviors in the context of a naturalistic social interaction. To best capture how children communicate during this social interaction, we have devised a micro-analytic coding scheme that will reveal which channels children use to convey information, as well as how they integrate these different channels. In the following studies, different components of communication will be assessed in individuals with typical development and children with neurodevelopmental disorders of different natures and origins. Our groups include: Typically Developing (TD) children, children with High Functioning Autism (HFA), children with Williams Syndrome (WS), and children with Perinatal Stroke (PS). The majority of research regarding communication in these groups has focused on infants, toddlers, and younger preschool children, before the children are proficient language users. In studying school age children, we can determine how communication is distributed across multiple communicative channels, now that language has become their primary communicative system. Studying TD children can provide a greater understanding of the range and nature of typical development and can help identify and create more appropriate therapeutic interventions for individuals exhibiting abnormal social and emotional behaviors. Individuals with neurodevelopmental disorders often have significant impairments in social communication that impact their relationships with others. In Chapter 2, a literature review on the communicative behaviors regarding each of our groups of children is presented. Chapter 3 is devoted to an investigation of social communication in TD school age children. Chapter 4 focuses on the social and affective components of communication in children with HFA and children with WS. Chapter 5 investigates the use and integration of language and emotional expression in school age children with PS. These studies make a significant contribution toward understanding the interrelationships of the social and affective components of communication in school age children.