First described in the 1860s by the British physician J. Langdon Down (cf. Dunn, 1991), Down syndrome has been the subject of countless studies over the intervening 160 years. Studies have addressed such diverse issues as maternal age at birth; genetics, cytogenetics, and animal models; early health and physical issues; early (and later) cognitive, linguistic, and motor development; trajectories of development; adaptive behavior, personality, and maladaptive behavior/psychopathology; neuropsychological profiles; reading and other educational issues; mothers, fathers, siblings, and families of persons with Down syndrome throughout the lifespan; transition to adulthood and adult functioning; aging and Alzheimer's disease; and lifespan, morbidity, and mortality (including causes of death). A seemingly well-established area of research, which even 40 years ago was the subject of a 350-page review (Gibson, 1978), Down syndrome may be the topic of as many published studies as all other genetic conditions associated with intellectual disability (ID) combined (Hodapp & Dykens, 2012).In a similar way, Down syndrome is increasingly well-known by society at large. In many U.S. Presidential election seasons, the syndrome gets mentioned in candidate debates, with public calls to help these individuals. Several well-known television-movie stars have Down syndrome, including Chris Burke (Life Goes On) and Lauren Potter (Glee), and the syndrome