The Jensen box was developed by

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

psychologist A psychologist is a professional who practices psychology and studies mental states, perceptual, cognitive, emotional, and social processes and behavior. Their work often involves the experimentation, observation, and interpretation of how indi ...

Arthur Jensen Arthur Robert Jensen (August 24, 1923 – October 22, 2012) was an American psychologist and writer. He was a professor of educational psychology at the University of California, Berkeley. Jensen was known for his work in psychometrics an ...

as an experimental apparatus for measuring choice

reaction time Mental chronometry is the scientific study of processing speed or reaction time on cognitive tasks to infer the content, duration, and temporal sequencing of mental operations. Reaction time (RT; sometimes referred to as "response time") is meas ...

(RT) and individual differences in

intelligence Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. More generally, it can b ...

Design and measurement

The standard Jensen box is approximately 12 by 20 inches in size with a sloping face. Eight buttons are arrayed in a semicircle with a 'home' key in the lower center. Above each response button is a small

LED A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...

light. Following an auditory warning tone and a delay, one of the lights is illuminated and the participant releases their finger from the home button. Participants then move to initiate a button press at the illuminated location as quickly as possible. RT is measured in two different ways: the time elapsed between the light signal and the home button release, and the time between the home button release and the target button press. These separate measures were initially conceptualized as assessing "decision time" and "movement time," respectively. However, participants can shift decision time into the movement phase by releasing the home button while the decision-making is still incomplete. Masking the stimulus light can eliminate this artifact. Several additional parameters can be extracted. The slope of RTs when 1, 2, 4, and 8 light choices are presented is used to index the rate of information processing.

Variance In probability theory and statistics, variance is the expectation of the squared deviation of a random variable from its population mean or sample mean. Variance is a measure of dispersion, meaning it is a measure of how far a set of numbers ...

standard deviation In statistics, the standard deviation is a measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the mean (also called the expected value) of the set, while ...

in intra-individual RTs can be extracted to measure individual differences in response variability.

Findings

Following Hick's law, RTs slow as a function of the number of presented choices. Button presses are fastest when only one button is shown and slowest when all eight possible response buttons are available. Simple reaction time correlates with general cognitive ability, and there is some evidence that the slope of responding on the Jensen box does as well.

Ian Deary Ian John Deary OBE, FBA, FRSE, FMedSci (born 1954) is a Scottish psychiatrist known for work in the fields of intelligence, cognitive ageing, cognitive epidemiology, and personality. Deary is Professor of Differential Psychology at The Uni ...

and colleagues, in a population-based

cohort study A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing ...

of 900 individuals, demonstrated

correlations In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistics ...

between IQ and simple choice RTs between –0.3 and –0.5. The Jensen box has also been used on the Odd Man Out test.

References

{{Reflist Cognitive tests Intelligence tests

Design and measurement

Findings

See also

References