Answer to Question 1
Simply stated, the developmental-versus-difference controversy is this: Do all children regardless of intellectual impairmentsprogress through the same developmental milestones in a similar sequence, but at different rates? Or do children with intellectual disability develop in a different, less sequential, and less organized fashion?
Answer to Question 2
This link is found primarily among children in the mild intellectual disability range; children with more severe levels are identified almost equally in different racial and economic groups. Whether or not signs of organic etiology are present, diagnoses of mild intellectual disability increase sharply from near zero among children from higher SES categories to about 2.5 in the lowest SES category (APA, 2000). These figures indicate that SES factors play a suspected role both in the cause of intellectual disability and in the identification and labeling of persons with intellectual disability.
