Advances in medical care have allowed a greater number of neonates to survive. The result has been an increase in the number of infants at risk for later intellectual retardation. Happily, 80 to 90% of high-risk infants are intellectually normal later in life. Unfortunately, no valid screening device for differentiating infants who will later be intellectually normal from those who will be retarded is available. The development of such a device would have several advantages. One advantage is that parents of the majority of infants screened could be relieved of their anxiety and encouraged to treat their infants as intellectually normal. A second advantage is that identification of mental retardation during infancy may allow a fuller understanding of the causes of such deficit. The ultimate goal of the proposed research is to make a valid screening device available to clinicians so that infants who will later be intellectually normal or mentally retarded may be identified during the first year of life. The Fagan Test of Infant Intelligence (copyright JF Fagan, III) is a valid screening device for the early identification of later metal retardation. Until recently, the Fagan Test existed soley as a research instrument. However during an SBIR, Phase I, grant (9/85 - 3/86), a prototype of a clinically useful screening device was developed. The distribution of the clinical prototype for an extensive clinical trial is the main aim of the Phase II project. Ultimately, the prevention or remediation of mental retardation is more likely when early identification of the victims and the cause of mental retardation can be made. The commercial development of a valid screen device for the early detection of intellectual deficit promises to aid in diagnosing, understand and potentially, in preventing or alleviating mental retardation.