Abstract
Over the past 20 years, increasing numbers of studies have examined the etiology-related behaviors in children with genetic mental retardation syndromes. In this article, we focus on the clinical aspects of such behaviors for interventionists working with young children. After reviewing the concept of behavioral phenotype, we discuss how etiology-related strengths and weaknesses gradually emerge with age and, potentially, interact with environmental input (emergentism). Second, given that children with different genetic disorders show diverse profiles of strengths and weaknesses, this article discusses how interventionists can best provide more focused and more effective interventions.