The test has been shown to be much more influenced by age, apart from intelligence, than most other tests of the scale. Notwithstanding this fault, it seems desirable to keep the test, at least as an alternative, because it forms one of a group which may be designated as tests of time orientation. The others of this group are: “[Distinguishing forenoon and afternoon]” (VI), “[Giving the date]” and “[Naming the months]” (IX). It would be well if we had even more of this type, for interest in the passing of time and in the names of time divisions is closely correlated with intelligence. One reason for the inferiority of the dull and feeble-minded in tests of this type is that their mental associations are weaker and less numerous. The greater poverty of their associations brings it about that their remembered experiences are less definitely located in time with reference to other events.
The test was located in year IX of the 1908 scale, but was omitted from the 1911 revision. Kuhlmann also omits it, while Goddard places it in year VIII. The statistics from every American investigation, however, warrant its location in year VII. It may be located in year VIII only on the condition that the child be required to name the days backwards, and that within a rather low time limit.
VII, Alternative test 2: repeating three digits reversed
Procedure. The digits used are: 2–8–3; 4–2–7; 5–9–6. The test should be given after, but not immediately after, the tests of repeating digits forwards.
Say to the child: “Listen carefully. I am going to read some numbers again, but this time I want you to say them backwards. For example, if I should say 1–2–3, you would say 3–2–1. Do you understand?” When it is evident that the child has grasped the instructions, say: “Ready now; listen carefully, and be sure to say the numbers backwards.” Then read the series at the same rate and in the same manner as in the other digits tests. It is not permissible to re-read any of the series.
If the first series is repeated forwards instead of backwards series exhort the child to listen carefully and to be sure to repeat the numbers backwards.
Scoring. The test is passed if one series out of three is repeated backwards without error.
Remarks. The test of repeating digits backwards was suggested by Bobertag in 1911, but appears not to have been used or standardized previous to the Stanford investigation.
It is very much harder to repeat a series of digits backwards in the direct order at year VII, and six at year X. Reversing the order places three digits in year VII, four in year X, five in year XII, and six in “average adult.” Even intelligent adults sometimes have difficulty in repeating six digits backwards, once in three trials.
As a test of intelligence this test is better than that of repeating digits in the direct order. It is less mechanical and makes a much heavier demand on attention. The digits must be so firmly fixated in memory that they can be held there long enough to be told off, one by one, backwards.