UC San Diego

Children are exposed to a multitude of sensations on a daily basis. These sensation can be in the form of sensory input - such as visual, auditory, or tactile sensations - or in the form of social input - such as facial expressions, eye gaze, or body language. However, variation within children can influence the proficiency with which they recognize and interpret these sensory and social cues, as well as their ability to use social cues in the completion of social behaviors. While children can differ on a variety of dimensions, this dissertation examined two common sources of variation: characteristics of Autism Spectrum Disorder (ASD) and differences in temperament. Utilizing a questionnaire designed to assess sensory difficulties, in Chapter One I demonstrate that risk for, and diagnosis of, ASD influence children's reactions to low level sensory stimuli, such that they engage in an increased prevalence of atypical sensory behaviors in comparison to children without risk for, or diagnosis of, ASD. In Chapter Two, I demonstrate that toddlers' social behaviors (i.e., smiling, vocalizations, eye gaze) during an imitation paradigm differ in response to positive and neutral displays of facial and vocal affect from a partner, but that variation in temperament does not have an influence on these social behaviors. Chapter Three provides evidence that variation in social communication ability (as measured by the presence of autistic traits) in typically developing children negatively impacts their ability to engage in prosocial behaviors according to parent-report, regardless of their ability to attend to social cues in their environment during an in-lab prosocial paradigm. Taken together, these three chapters demonstrate that characteristics of ASD impact children's response to their sensory environment and completion of social behaviors, but temperamental variation does not play a strong role in children's response to their social environment.