Clocking the Mind: Mental Chronometry and Individual Differences (Hardcover)

~ Arthur R. Jensen (Author)
Key Phrases: chronometric research, worst performance rule, chronometric tests, American Psychological Association, Columbia University, Raven Advanced Progressive Matrices (more...)

Editorial Reviews

Review

"Jensen's writing is clear and concise, and every chapter is densely packed with information. The historical treatment of chronometry is perhaps most enjoyable, filled with personal anecdotes and unique insight into the politics of 20th century psychology and psychometrics."
Chris Chatham for DEVELOPING INTELLIGENCE (http://develintel.blogspot.com/2006/12/12/review-clocking-mind.html)

Product Description

Mental Chronometry (MC) comprises a variety of techniques for measuring the speed with which the brain processes information.
First developed in mid-1800, MC was subsequently eclipsed by more complex and practically useful types of psychometric tests stemming from Alfred Binet. This class of mental tests, however, has no true metric relating the test scores to any specific properties of the brain per se. The scores merely represent an ordinal scale, only ranking individuals according to their overall performance on a variety of complex mental tasks. The resulting scores represent no more than ranks rather than being a true metrical scale of any specific dimension of brain function. Such an ordinal scale, which merely ranks individuals in some defined population, possesses no true scale properties, possessing neither a true zero or equal intervals throughout the scale. This deficiency obstructs the development of a true natural science of mental ability. The present burgeoning interest in understanding individual differences in mental abilities in terms of the natural sciences, biology and the brain sciences in particular, demands direct measures that functionally link brain and behavior. One such natural ratio scale is time itself - the time it takes the brain to perform some elementary cognitive task, measured in milliseconds.
After more than 25 years researching MC, Jensen here presents results on an absolute scale showing times for intake of visual and auditory information, for accessing short-term and long-term memory, and other cognitive skills, as a function of age, at yearly intervals from 3 to 80 years. The possible uses of MC in neurological diagnosis and the monitoring of drug effects on cognition, the chronometric study of special time-sensitive talents such as musical performance, and presents a theory of general intelligence, or g, as a function of the rate of oscillation of neural action potentials as measured by chronometric methods. Finally, Jensen urges the world-wide standardization of chronometric methods as necessary for advancing MC as a crucial branch of biopsychological science.

*Provides a different scale to report Mental Chronometry (MC) findings
*Argues for the global adoption of an absolute scale as opposed to the traditional ordinal scale
*An important contribution to MC researchers and psychologists and neuroscientists

Product Details

• Hardcover: 286 pages
• Publisher: Elsevier Science; 1 edition (September 13, 2006)
• Language: English
• ISBN-10: 0080449395
• ISBN-13: 978-0080449395
• Product Dimensions: 9.4 x 6.5 x 1 inches
• Shipping Weight: 1.5 pounds (View shipping rates and policies)
• Average Customer Review: 4.0 out of 5 stars  See all reviews (1 customer review)
• Amazon.com Sales Rank: #1,575,923 in Books (See Bestsellers in Books)

Customer Reviews

Most Helpful Customer Reviews

19 of 20 people found the following review helpful:

4.0 out of 5 stars Depth and Breadth: A scholarly monograph on a set of surprising and unpopular findings, December 18, 2006

By	Chris Chatham (Boulder, CO) - See all my reviews

Arthur Jensen is a controversial figure in psychology, due in large part to claims about racial differences in intelligence. In his newest book, "Clocking the Mind," Jensen turns his attention to a more focused, yet still controversial topic: how is it that extraordinarily simple measures of reaction time can correlate so highly with intelligence?

To understand the importance of this question, consider the following. First, as Jensen notes, almost all reliable measures of cognitive performance are correlated. Across a large number of such tests, a single number - termed g, for "general intelligence" - can account for a large portion of individual differences on each task. Because no single test is "process pure," the correlations between g and scores on any given test are typically rather small; high correlations emerge from these measures only when they are considered in aggregate, with the following exception.

Despite the fact that g is commonly assessed with tests of vocabulary, memory for associations, reasoning ability on the Raven's Progressive Matrices (where subjects must discover a visual pattern within a matrix of stimuli, and select what the next pattern in the sequence would look like), and a wide variety of other very abstract and untimed tests, it appears that the variance they share can be reliably and accurately indexed by reaction time on a task where subjects must merely press a lighted button. The correlations between such simple tasks and g is around .62, which is higher than the correlation between many subscales of IQ tests and the g factor to which they contribute.

If you are skeptical of these results, you are not alone. Jensen notes a deep-seated bias against the idea that such simple measures could reveal important traits of the cognitive system, and reviews several historical reasons for this bias. However, in just over 200 pages, Jensen creates a persuasive argument for the RT-IQ correlation based on dozens of factor analyses, and both developmental and genetic work. In the process, he covers issues related to statistical methodology, procedural variations on simple RT tasks, and correlations between simple RT and Sternberg memory scanning, working memory, short-term memory, long term memory, and a variety of other cognitive constructs.

In the end, it appears that simple RT and g may be very closely related, if not indexing the same thing. Jensen advocates the "bottom-up" interpretation of the RT-IQ correlation, suggesting that individual differences in processing speed allow those individuals to think faster, accumulate more information per unit time, and provide other advantages that subsequently translate into g. Jensen notes that the "top-down" interpretation - for example, that increased IQ leads to better strategy-use, and for that reason result in lower RTs on simple tasks - is plausible but relatively uninteresting for those interested in mechanistic rather than merely descriptive accounts of intelligence. Whether or not you agree with Jensen's "neural oscillation" hypothesis of the RT-IQ correlation, these facts beg for a mechanistic explanation.

Jensen's writing is clear and concise, and every chapter is densely packed with information. The historical treatment of chronometry is perhaps most enjoyable, filled with personal anecdotes and unique insight into the politics of 20th century psychology and psychometrics. My only complaint is the index seems sparse for a book so rich in detail.

"Clocking the Mind" is not a popular science book; it is a scholarly work directed towards professionals and graduate students. Yet, anyone with a scientific interest in individual differences, intelligence, or executive functions will find much to consider here. After all, if Jensen is right, relatively simple and extremely reliable measures of reaction time might be a good replacement for some of the "fancy tasks" cognitive scientists have spent decades refining.