Elkind, D., Koegler, R. R. & Go, E. (1964). Studies in perceptual development: II. Part-whole perception. Child Development, 35, 81-90.

One hundred and ninety-five children from 4 to 9 years of age were tested for their ability to perceive both parts and wholes in drawings wherin both parts and wholes had independent meanings. Results showed (a) regular increase with age in ability to perceive part and whole, (b) parts perceived at an earlier age than wholes, and (c) part and whole integration present in a majority (75 per cent) of children by age 9. The results were interpreted from the standpoint of Piaget's genetic theory of perception.