The constancy of the intelligence quotient as indicated by retests of 130 children

Abstract

100 subjects were tested first at an average age of 4 years by the Merrill-Palmer, Terman-Merrill, or 1916 Stanford-Binet tests and were retested at an average age of 9 years 5 months by the Terman-Merrill test. 30 subjects were tested by an individual test at about 10 years and retested by the ACE test after about 7 years. Changes in IQ (average changes for groups, per cent of persons showing gain or loss or no change, and per cent of subjects showing changes within specified limits) are tabulated for the 100 subjects grouped according to interval between tests, level of IQ, sex, tests used, and ages at which tests were given. The total group of 100 subjects showed an average gain of 8 IQ points, with 48% of the group showing a gain or loss of more than 10 points. For the 30 subjects only average test results are compared. Correlations, ranging from .22 to .59, are reported between test and retest results for various groupings. Brief case studies are presented for 11 cases in which there were marked changes in IQ. Reasons for the changes are suggested. (PsycInfo Database Record (c) 2025 APA, all rights reserved)