James McKeen Cattell's Tests of Mental Abilities

Published in the journal Mind in 1890

Cattell's rationale for administering the tests:

The results would be of considerable scientific value in discovering the constancy of mental processes, their interdependence, and their variation under different circumstances. Individuals, besides would find their tests interesting, and, perhaps, useful in regard to training, mode of life or indication of disease (Cattell 1890, p. 1).

The test battery, with some subtests borrowed from Frances Galton, consisted of the following ten measures:

  1. Dynamometer pressures: this test measures the degree of pressure a person can exert by squeezing an instrument with his/her right and left hands. Cattell aimed to study the relation between bodily power, as indicated by the power of the hand squeeze, and a persons "volitional control" or "emotional excitement."
  2. Rate of movement: This test measures the rate at which the right hand and arm proceeds from rest through a 50 centimeter swing. Cattell recommends using an apparatus in which an electric current is closed by the first movement of the hand and broken when the movement has been completed, so that the time of the excursion can be recorded. He was interested in the rate of movement and the "four temperaments."
  3. Sensation-areas: This test measures the just noticeable difference between two points on the skin. He recommends the back of the hand and used a compass with wooden tips, with a curvature radius set at 5 mm. Cattell recorded the distance at which his "examinee" begins to distinguish the two ouches.
  4. Pressure causing pain: For this test, Cattell measures the pressure by using an instrument with a hard rubber tip (with a 5 mm radius). He applies the instrument to the center of the forehead and gradually increases the pressure until the experimentee says it is painful. His aim for this measure is for its use in diagnosing nervous diseases and studying abnormal states of consciousness.
  5. Least noticeable difference in weight: Here, Cattell uses a small wooden box, weighing 100 grams, and has the experimentee compare its weight with others (101 grams, 102, grams up to 110 grams.). The experimentee is asked which is heavier and Cattell records the point at which the person is usually right.
  6. Reaction time for sound: This is a measure of "time elapsing before a stimulus calls forth a movement" (Cattell, 1890, p. 2). Cattell measures this with a Hipp chronoscope, calculating an average of three measures.
  7. Time for naming colors: This Cattell considers this task more mental than reaction time measures above, which he considers to be "essentially reflex." In this task, Cattell shows his experimentees 10 colors, and measures the length of time it takes for them to name all ten.
  8. Bisection of a 50 cm line. The experimentee divides an ebony rule (3 cm. wide) into two equal parts, using a moveable line. The error (distance from the midline) is recorded and whether it is to the right or left.
  9. Judgment of a 10 second time: Cattell strikes the table with the end of a pencil and again after 10 seconds. The experimentee is asked to repeat the act. Cattell records the time difference between the correct and error judgment.
  10. Numbers of letters repeated on one hearing: Cattell orally gives six consonant sounds to subject, one second apart. He increases or decreases the number to determine the maximum number that can be grasped.