Publisher Summary This chapter discusses the interplay between motivation and etiology‐specific strengths and weaknesses in cognitive–linguistic functioning. The chapter presents a brief review of research on motivation in children with idiopathic developmental delays. It discusses evidence for within‐individual and task‐specific variability in motivational orientation. Most research in mental retardation has considered motivation to be a domain‐general construct, but this chapter review evidence that individuals change motivational orientations in response to different types of tasks. The idea of differential motivation is discussed in the context of cognitive–linguistic phenotypes in Down syndrome and Williams syndrome: the role that motivation plays in helping to shape outcomes (progressive modularization of language in Williams syndrome), and the role motivation can play in modifying developmental outcomes (cognitive–linguistic intervention in Down syndrome). This exploration is an important first step toward designing motivation‐oriented interventions that prevent or ameliorate early syndrome‐specific failure experiences and maximize early successes.