A turkey feather was drawn representatively, drawn analytically, and described verbally by 51 high school pupils. Twenty-four hours after the analytical drawing, the pupils were again required to make a diagram of the feather and to answer questions about its parts. The results of these various efforts were then scored by ten competent judges independently, to obtain a final score for each pupil in each test.
The table, from Ayer, on page [149], shows the rank obtained by each pupil in each kind of performance. The pupil who stands first in memory stands thirty-eighth in representative drawing, and so forth down the series, for each pupil.
In the following table, from Ayer, we see the coefficients of correlation found between the various functions tested, as computed from the ranks listed in the table on page [149].
| Table from Ayer | |
|---|---|
| Showing correlations in case of representative drawing, retention, diagramming (analytical drawing), and description. | |
| Abilities Correlated | Coefficient of Correlation (Pearson) |
| Representative drawing and description | .023 |
| Diagramming and representative drawing | −.052 |
| Diagramming and description | .231 |
| Representative drawing and retention | −.022 |
| Description and retention | .234 |
| Analytical drawing and retention | .433 |
| Table from Ayer | |||
|---|---|---|---|
| Rank in retention, representative drawing, description, and analytical drawing, as tested in the case of 51 students in a first year high school class in general science. | |||
| Rank in Memory | Rank in Drawing | Rank in Description | Rank in Diagram |
| 1 | 38 | 2 | 1 |
| 2 | 41 | 14 | 5 |
| 3 | 37 | 1 | 14 |
| 4 | 22 | 30 | 41 |
| 5 | 7 | 46 | 4 |
| 6 | 17 | 20 | 10 |
| 7 | 48 | 22 | 43 |
| 8 | 27 | 19 | 6 |
| 9 | 42 | 6 | 27 |
| 10 | 39 | 9 | 31 |
| 11 | 31 | 44 | 19 |
| 12 | 36 | 10 | 9 |
| 13 | 18 | 41 | 26 |
| 14 | 21 | 29 | 12 |
| 15 | 9 | 38 | 23 |
| 16 | 35 | 13 | 35 |
| 17 | 51 | 37 | 24 |
| 18 | 25 | 35 | 39 |
| 19 | 10 | 24 | 34 |
| 20 | 26 | 5 | 25 |
| 21 | 12 | 17 | 30 |
| 22 | 28 | 49 | 51 |
| 23 | 34 | 25 | 13 |
| 24 | 3 | 12 | 15 |
| 25 | 45 | 45 | 3 |
| 26 | 24 | 7 | 2 |
| 27 | 6 | 32 | 47 |
| 28 | 16 | 34 | 18 |
| 29 | 20 | 31 | 8 |
| 30 | 4 | 50 | 22 |
| 31 | 44 | 18 | 40 |
| 32 | 19 | 4 | 17 |
| 33 | 13 | 48 | 45 |
| 34 | 33 | 16 | 33 |
| 35 | 11 | 8 | 44 |
| 36 | 23 | 47 | 36 |
| 37 | 1 | 43 | 38 |
| 38 | 43 | 33 | 29 |
| 39 | 8 | 36 | 11 |
| 40 | 29 | 42 | 21 |
| 41 | 30 | 3 | 46 |
| 42 | 2 | 26 | 42 |
| 43 | 47 | 28 | 28 |
| 44 | 32 | 21 | 7 |
| 45 | 15 | 27 | 20 |
| 46 | 46 | 39 | 47 |
| 47 | 49 | 11 | 16 |
| 48 | 50 | 40 | 50 |
| 49 | 5 | 45 | 30 |
| 50 | 40 | 23 | 48 |
| 51 | 14 | 51 | 49 |
The correlation between representative drawing and verbal description is practically zero. From knowledge of ability in one of these functions, among high school students, no inference can be made concerning the other. Ability in diagramming (a kind of analytical drawing) is also not correlated with representative drawing. On the other hand, the processes of diagramming and description exhibit a slight tendency to positive coherence, as do description and retention. Analytical drawing and retention have a decided tendency to cohere, with a coefficient of .433.
In order to check his finding that school marks in drawing correlate well with school marks in other subjects, Ayer correlated the scores of these 51 high school pupils in representative drawing, with their school marks and found an absence of relationship. “Ability in representative drawing is not correlated with achievement in school subjects, when it is isolated from the other factors of school drawing.”
Ayer concludes that different kinds of drawing are differently correlated with general intelligence, and that it is necessary to isolate the various kinds in determining the relationship. Analytical drawing is a better indication of a pupil’s general grasp of subject matter than is representative drawing. He recommends “that the device of representative drawing shall be supplanted in laboratory teaching,” since it appears to be a highly specialized function.
The question of the relationship between general intelligence and ability to draw has also been investigated by Manuel, who took the IQ of each of his talented subjects by means of Stanford-Binet. These were pupils in elementary school, high school, and college. This means of measuring general intelligence was ill adapted to its purpose in the case of the college students and, also, probably in the case of many of the high school students among his subjects, as the scale will not measure the intelligence of very superior adolescents and adults. Because of its limitations, the most intelligent adult in the world cannot show an IQ of more than about 120 on it. Therefore some of Manuel’s older subjects may have been much more intelligent than appears on the record. The range of intelligence among those talented in drawing may be even greater than the record shows. The tests as they stand show that superior ability in drawing may accompany any degree of general intelligence from very superior to very inferior. “We conclude therefore that a certain elementary ability in graphic representation, such as is required for success in elementary school drawing, is independent, or partially independent, of general intelligence.”
It should be stated that presence of talent in drawing in the case of these individuals was determined in part by testimony of teachers of art, and in part by two tests, (1) the drawing of a house from memory, and (2) the drawing of a wooden cart from the object. Both of these would be classified as representative drawings.