Extrapolated Stanford-Binet IQs for Severely and Profoundly Retarded Adults

Abstract

The 1972 table of norms for the Stanford-Binet Intelligence Scale does not include scores for adults who achieve Mental Ages (MA) below 5–3. To standardize assignment of IQ for severely and profoundly retarded adults scoring in this range, a regression analysis of the 1972 tabled values at the Chronological Age (CA) 18–0 level was performed. From the resulting regression equation, a table containing extrapolated IQs for MAs 2–0 through 5–11 was produced which can be used to standardize estimates of IQ for low-functioning adults.