The Correlation of the Reverse Audito-Vocal Digit Memory Span with the General Intelligence and Other Mental Abilities of 308 Prisoners

The purpose of this study is to determine the amount of correlation, if any, between the reverse audito-vocal digit memory span and the following: (1) General intelligence, (2) Vocabulary, (3) Interpretation of fables, (4) Chronological age. The Intelligence Quotient obtained by means of the Stanford Revision of the Binet-Simon Tests was used as a measure of general intelligence. The reverse audito-vocal digit memory span, the vocabulary, and the ability to interpret fables were measured by the individual tests for these abilities contained in the Binet-Simon series. The procedure in administering these tests and the method of scoring them were the standardized procedure and method described in "The Measurement of Intelligence."1 The subjects of this investigation were originally 507 prisoners, 331 white and 176 colored, of the Eastern State Penitentiary of Pennsylvania. Thirty-five of these prisoners were tested by myself while the remainder were tested by Mr. J. D. Shearer, Psychologist and Director of Education of the Penitentiary. Of the total number of cases investigated, however, 199 were rejected because they had not passed a reverse audito-vocal digit memory span test. For example, if a subject's basal age should be ten and if he should fail to pass the reverse audito-vocal digit memory span test for five digits at the twelve-year level, then the record would show what he could not do and not what he could do with respect to the reverse audito-vocal digit memory span since there is no test for this ability at the ten-year level. It might be assumed that he could have passed the test for four digits in reverse order which is located at the nine-year level, but this would be an assumption and not an established fact. The study is thus confined to 308 cases of whom