This program has provided interdisciplinary post-doctoral training in behavioral and biobehavioral research on intellectual and developmental disabilities (IDD) since 1995, with an emphasis on social-affective, communicative, and family processes. We have enrolled and graduated 35 post-doctoral fellows, of whom 24 occupy faculty positions at universities across the US and almost all others have obtained research-related positions in the field. The training program is housed at, and fully integrated into, the rch training environment of the University of Wisconsin-Madison's Waisman Center, a multidisciplinary translational research center that includes an NICHD-funded Intellectual and Developmental Disabilities Research Center, over 90 NIH research grants, and a thriving clinical program serving 3500 patients/yr. The overall purpose of the training program is to provide intensive mentoring by program faculty and a robust series of seminars, so that trainees gain a broad base of knowledge about human development and developmental disabilities and are prepared for independent careers engaged in and advancing scientific research on IDD. The program has three Specific Aims: 1. To provide post-doctoral trainees with the knowledge base and research methods to generate new knowledge about social, communicative, and family components of IDD. 2. To provide broad training in which we expose trainees to various theoretical perspectives, methodological approaches, substantive areas, developmental periods, and a translational science perspective. 3. To provide trainees with a solid foundation in ethics and professional development necessary to launch successful careers carrying out research on IDD. Support for this program will ensure that a next generation of scientists receives broad training to ensure continued advances in understanding and treating IDD conditions through various theoretical perspectives, methodological approaches, substantive areas, developmental periods, and a translational science/public health perspective.