Knox Cubes
The Knox Cube Imitation Test (KCIT, or CIT, or KCT) 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 (1-2-3-4) is reasonable for a child of 4 years of age, sequence b (1-2-3-4-3) is suitable for a 5-year-old, sequence c (1-2-3-4-2) can be accomplished by a 6-year-old, sequence d (1-3-2-4) can be done by the average  8-year-old, and copying sequence e (1-3-4-2-3-1) is expected by most 11-year-olds. Some of these sequences were repeated as part of other published tests such as Arthur (1947) and Wright & Stone (1979). Performance on the Knox Cube Imitation Test is correlated with both Verbal IQ and Performance IQ.