Knox Cubes


The Knox Cube Imitation Test was developed as a nonverbal intelligence test developed by Dr. Howard Andrew Knox, a medical officer at Ellis Island. It was first published as a pamphlet in 1913, and then in 1914 as a paper in the Journal of the American Medical Association.
Knox wrote:
There were several other tests presented in his paper besides the cube test. In the cube test, 4 black 1" cubes were placed in a row, each cube separated by 4 inches from its neighbors. The test administrators takes a smaller cube and taps on the 4 1" cubes in increasing complicated sequences. The test subject is requested, sometimes only by sign language, to repeat the sequence. If the cubes are numbered 1 through 4, the sequences in order are:
and so on.
Knox suggested that sequence a is reasonable for a child of 4 years of age, sequence b is suitable for a 5-year-old, sequence c can be accomplished by a 6-year-old, sequence d can be done by the average 8-year-old, and copying sequence e is expected by most 11-year-olds. Some of these sequences were repeated as part of other published tests such as Arthur and Wright & Stone.
Performance on the Knox Cube Imitation Test is correlated with both Verbal IQ and Performance IQ.