Abstract
Ability of copying forms, including stereographic figures, was studied with 149 normal children (from Kindergarten to 2nd year grade of elementary school) and 64 mentally retarded children (7-16 years, from imbecile to borderline).
Ten forms were used: a, circle; b, square; c, circle divided by an S line; (these are named “simple forms”); d, two triangles making, a butterfly; e, diamond; f, two triangles intercrossing; g, two hexagons having a line in common; h, triangle with inscribed triangles; (“oblique-line forms”); i, cylinder; j, cube; (“stereographic figures”).
Copies were evaluated and scored by the following principles.
3 marks; motif of the model is correctly realized. 2 marks; a little deformed, but the dominant features of the model are represented permissibly.1 mark; important features of the model are missing. 0 mark; all traits of the model are missing.
Results
(1) Mean scores of each form for each group of Ss:
For Kindergarten children (mean MA, 6 yrs. 6 mths.); a, 3 b, 2.7 c, 2.1 d, 1.8 e, 1.9 f, 1.6 g, 1.6 h, 1.9 i, O.9 j, 0.8.
For 2nd year grade Ss.; a, 3 b, 3 c, 2.9 d (not obtained) e, 2.9 f, 2.7 g, 2.8 h, 2.6 i, 2.3 j, 1.5. For mentally retarded Ss. of elementary school (mean MA, 6 yrs. 2 mths.); a, 2.3 b, 2.2 c, 1.4 d (not obtained) e, 1.2 f, 1.0 g, 0.9 h, 1.3 i, 0.9 j, 0.5.
For mentally retarded group of lower secondary school (mean MA, 7 yrs. 7 mths.); a, 2.7 b, 2.6 c, 2.1 d, 2.6 e, 2.6 f, 2.6 g, 2.4 h, 2.6 i, 1.9 j, 1.4.
(2) Cube was copied by only some of those who are beyond 8 years of MA, and only 30% of the normal Ss. and several borderline children of more than 12 years of CA could accomplish it.
(3) It is an intellectual operation for a child to copy a cube, and it depends on MA level, not on manual dexterity. Many other sensori-motor skills have been acquired originally through more or less intellectual processes.
(4) Rough grades of copying ability (only simple forms; some of oblique form; mastering obl.; etc.) have correlation with intelligence even within the range of normal Ss.
(5) The ways of drawing a cube can be classified into several groups, which have some correlation with general ability.
