The use of language in social contexts, or pragmatic skills, are essential for daily communication. This study compares the developmental trajectories of these skills. Determining whether a pragmatic skill is either unique to fragile X syndrome (FXS) or related to other conditions, such as gender, mental retardation, or autism, may help in defining treatment options for fragile X in males. In this study, children's pragmatic skills, including their initiations, contingency, perseveration, and repair strategies during conversation and their informativeness and cohesiveness during narration will be assessed annually for four years. Children's language content and structure, cognition, social-emotional behavior (anxiety and autistic characteristics), and family environment will also be examined annually. In addition, Fragile X Mental Retardation Protein (FMRP) analysis from blood samples will be completed on the girls and boys with FXS. These studies may indicate a unique pragmatic phenotype for FXS.