A comparative study of the intelligence quotient and Heinis' personal constant

Abstract

Re-test of 433 children ranging in age from 6 to 13 years and in IQ from 50 to 100 shows that the personal constant is a "more accurate expression of the rate of mental development" than the intelligence quotient. Correlation between first and second test for PC and IQ respectively are + .83 ± .101 and + .77 ± .132. A review of literature on the constancy of IQ and PC is included. (PsycInfo Database Record (c) 2025 APA, all rights reserved)