The perceptions of parents of 113 developmentally delayed preschool children were compared with mental ages derived from the Cattell Infant Intelligence Scale and the Stanford Binet Intelligence Scale. With the parents as informants, an Alpern-Boll Developmental Profile was completed. Findings demonstrated a high degree of correlation between the…

This final report reviews the second phase of a life-span study of boys with fragile X syndrome (FSX), the most common known inherited cause of mental retardation. Males with the syndrome are more severely affected than females and in males, delays are usually evident in all the developmental domains, although cognitive and communication skills…