Intelligence: Knowns and unknowns

Biometrics, 1998

1999

This paper reviews what is known about intelligence and the use of intelligence tests. Environmental and hereditary factors that affect performance on intelligence tests are reviewed, along with various theories that have been proposed about the basis of intelligence. Intelligence tests do not test intelligence per se but make inferences about a person's intelligence. Intelligence tests contain some measurement errors, and no single intelligence quotient (IQ) test or theory is uniformly accepted as the "best." It is suggested that the best way to test intelligence is to use a reliable battery of tests or combination of tests with many subcategories. These subcategories should reflect a wide range of abilities, processes, and contexts. In addition, the results of tests should be reported in a clear and analytical way. These reports should guide teachers and parents in helping each individual student in the most appropriate way. (Contains 3 figures, 3 tables, and 30 references.) (SLD) Reproductions supplied by EDRS are the best that can be made from the original document.

Canadian Psychology/Psychologie canadienne, 2009

There is no more central topic in psychology than intelligence and intelligence testing. With a history as long as psychology itself, intelligence is the most studied and likely the best understood construct in psychology, albeit still with many "unknowns." The psychometric sophistication employed in creating intelligence tests is at the highest level. The authors provide an overview of the history, theory, and assessment of intelligence. Five questions are proposed and discussed that focus on key areas of confusion or misunderstanding associated with the measurement and assessment of intelligence.

American Psychologist, 2012

We review new findings and new theoretical developments in the field of intelligence. New findings include the following: (a) Heritability of IQ varies significantly by social class. (b) Almost no genetic polymorphisms have been discovered that are consistently associated with variation in IQ in the normal range. (c) Much has been learned about the biological underpinnings of intelligence. (d) "Crystallized" and "fluid" IQ are quite different aspects of intelligence at both the behavioral and biological levels. (e) The importance of the environment for IQ is established by the 12-point to 18-point increase in IQ when children are adopted from working-class to middle-class homes. (f) Even when improvements in IQ produced by the most effective early childhood interventions fail to persist, there can be very marked effects on academic achievement and life outcomes. (g) In most developed countries studied, gains on IQ tests have continued, and they are beginning in the developing world. (h) Sex differences in aspects of intelligence are due partly to identifiable biological factors and partly to socialization factors.

Applied Measurement in Education, 2019

This brief article introduces the topic of intelligence as highly appropriate for educational measurement professionals. It describes some of the uses of intelligence tests both historically and currently. It argues why knowledge of intelligence theory and intelligence testing is important for educational measurement professionals. The articles that follow in this special issue will provide readers with considerable information about the history of intelligence theory and testing, and especially of the Cattell-Horn-Carroll (CHC) model of testing and its implementation. The following articles will also provide a well-reasoned approach to the way science should work in evaluating tests and the models on which they are based.

The previous article ended with the Cattell-Horn-Carroll (CHC) consensus model of a transcendent third order factor g and, an array of nine second order factors. This emerged near to the culmination of a series which has mainly focussed on the structure of human intelligence.

Due to the prevalence of IQ tests in Western cultures as a method of categorization (McClelland, 1973), intelligence testing has thus accumulated a large volume of literature. An objective definition of intelligence seems to have escaped the grasp of academics, with many conceptualisations of intelligence owing their origins to socio-cultural influences (Sternberg, 2000). The aim of this experiment was to examine intelligence testing measures and understand how to transform z scores into standardised IQ scores. Digit Span, a subset of the Working Memory Index of the WAIS-III was administered to 12 undergraduate university students. Participants were asked to perform two tasks independently of each other, Digit Span Forward (DSF), and Digit Span Backward (DSB). To ensure validity and objectivity in the administration of the test, the examiner was required to adhere to certain rules concerning voice inflection on the final number of a sequence, and speaking the numbers at a rate of one number per second. A more detailed procedure concerning examiner guidelines can be found in the method section of this report. Z scores were calculated from the participant’s raw data scores, which were then transformed into standardised IQ scores. The standardisation of z scores allows for a broader interpretation of an individual’s raw data scores in comparison to others of a similar age and demographic. Furthermore, in this experiment the validity of intelligence testing measures as accurate measures of intelligence was investigated.

2006