ABSTRACT
Retaining a child in a grade is a very popular educational practice for dealing with not only low academic achievement but also social immaturity. Schooling effects were found in that the group who just made the cutoff and was exposed earlier to formal reading instruction performed better in reading and short-term memory skills than did the group who just missed the cutoff and had to wait a year for formal reading instruction. The zebra syndrome, with its either/or logic, constrains learning because students are at the mercy of the way the pendulum of favored reading methods is swinging when they are in elementary school. Biological and educational constraints are confounded in static, one-shot measures of reading and writing achievement and of developmental skills related to reading and writing. The opportunity to learn must be carefully assessed before attributing reading and writing problems solely to biological constraints.
