This proposal to the National Institute of Child Health and Human Development/National Institutes of Health is an international conference proposal. The proposal seeks support for air travel costs for 28 U.S. invited scientists to speak at specific symposia organized as part of the Eighth International Congress of the International Association for the Scientific Study of Mental Deficiency (IASSMD). The congress is to be held in Dublin, Ireland, August 21-25, 1988. The specific symposia for which support is requested relate to topics on mental retardation and developmental disabilities. All of the participants for whom support is requested are U.S. scientists conducting research either at one of the nation's Mental Retardation Research Centers, or at one of the University Affiliated Facilities, or at other universities throughout the country. Many of these investigators have individual support from the NICHD and all are conducting research relevant to the interests of the Institute.