Posts Tagged: IQ

May 10

How To Score Eleven More IQ Points in Ten Minutes

The conclusion they came to: think out load.

How to Gain Eleven IQ Points in Ten Minutes: Thinking Aloud Improves Raven’s Matrices Performance in Older Adults

Mark C. Fox, Neil Charness


Few studies have examined the impact of age on reactivity to concurrent think-aloud (TA) verbal reports. An initial study with 30 younger and 31 older adults revealed that thinking aloud improves older adult performance on a short form of the Raven’s Matrices (Bors & Stokes, 1998, Educational and Psychological Measurement, 58, p. 382) but did not affect other tasks. In the replication experiment, 30 older adults (mean age = 73.0) performed the Raven’s Matrices and three other tasks to replicate and extend the findings of the initial study. Once again older adults performed significantly better only on the Raven’s Matrices while thinking aloud. Performance gains on this task were substantial (d = 0.73 and 0.92 in Experiments 1 and 2, respectively), corresponding to a fluid intelligence increase of nearly one standard deviation.


May 10

WORDSUM and IQ, and their Correlation

Often I’ve seen people use WORDSUM scores as a proxy for IQ. You may have seen it yourself, but wondered why people believe there is a correlation between the two. Razib Khan wrote up a nice post that explains it.

Every time I use the WORDSUM variable from the GSS people will complain that a score on a 10-question vocabulary test is not a good measure of intelligence. The reality is that “good” is too imprecise a term. The correlation between adult IQ and WORDSUM = 0.71. The source for this number is a 1980 paper, The Enduring Effects of Education on Verbal Skills.

Jason Malloy further makes the comment that…

I’ve linked this paper before as well. The WORDSUM is an IQ test, and not simply a “proxy” for IQ, as many have called it. This is determined by its construct validity.

It’s clearly tapping a cognitive dimension; vocabulary strongly correlates (.83) with the general intelligence factor: content validity. The WORDSUM correlation with the AGCT is within the range that IQ tests correlate with each other: concurrent validity. It is a reliable independent predictor and predicts external outcomes in a similar manner as other IQ tests: criterion validity.

I wouldn’t recommend it for clinical or admissions purposes, but the GSS is an adequate cognitive test for the purposes of the GSS.

Feb 10

General Intelligence Located In The Brain

There’s an interesting paper called "Distributed neural system for general intelligence revealed by lesion mapping". (It’s open access, so anyone can read it online.)

The paper claims to have found the regions of the brain associated with general intelligence.

Here’s an excepts from ScienceDaily….

A collaborative team of neuroscientists at the California Institute of Technology (Caltech), the University of Iowa, the University of Southern California (USC), and the Autonomous University of Madrid have mapped the brain structures that affect general intelligence.

The study, to be published the week of February 22 [2010] in the early edition of the Proceedings of the National Academy of Sciences, adds new insight to a highly controversial question: What is intelligence, and how can we measure it?

[The Scientists] examine[d] a uniquely large data set of 241 brain-lesion patients who all had taken IQ tests. The researchers mapped the location of each patient’s lesion in their brains, and correlated that with each patient’s IQ score to produce a map of the brain regions that influence intelligence.
The researchers found that, rather than residing in a single structure, general intelligence is determined by a network of regions across both sides of the brain.

“One of the main findings that really struck us was that there was a distributed system here. Several brain regions, and the connections between them, were what was most important to general intelligence,” explains Gläscher.

“It might have turned out that general intelligence doesn’t depend on specific brain areas at all, and just has to do with how the whole brain functions,” adds Adolphs. “But that’s not what we found. In fact, the particular regions and connections we found are quite in line with an existing theory about intelligence called the ‘parieto-frontal integration theory.’ It says that general intelligence depends on the brain’s ability to integrate — to pull together — several different kinds of processing, such as working memory.”

(Emphasis mine.)

Or in the words of the authors of the paper….

Distributed neural system for general intelligence revealed by lesion mapping

J. Gläschera, D. Rudraufc, R. Colome, L. K. Paula, D. Tranelc, H. Damasiof, and R. Adolphsa


General intelligence (g) captures the performance variance shared across cognitive tasks and correlates with real-world success. Yet it remains debated whether g reflects the combined performance of brain systems involved in these tasks or draws on specialized systems mediating their interactions. Here we investigated the neural substrates of g in 241 patients with focal brain damage using voxel-based lesion–symptom mapping. A hierarchical factor analysis across multiple cognitive tasks was used to derive a robust measure of g. Statistically significant associations were found between g and damage to a remarkably circumscribed albeit distributed network in frontal and parietal cortex, critically including white matter association tracts and frontopolar cortex. We suggest that general intelligence draws on connections between regions that integrate verbal, visuospatial, working memory, and executive processes.

Jan 10

Face Recognition: Another Cognitive Ability Separate From IQ

Recognizing faces is an important social skill, but not all of us are equally good at it. Some people are unable to recognize even their closest friends (a condition called prosopagnosia), while others have a near-photographic memory for large numbers of faces. Now a twin study by collaborators at MIT and in Beijing shows that face recognition is heritable, and that it is inherited separately from general intelligence or IQ.

This finding plays into a long-standing debate on the nature of mind and intelligence. The prevailing generalist theory, upon which the concept of IQ is based, holds that if people are smart in one area they tend to be smart in other areas, so if you are good in math you are also more likely to be good at literature and history. IQ is strongly influenced by heredity, suggesting the existence of “generalist genes” for cognition.

Yet some cognitive abilities seem distinct from overall IQ, as happens when a person who is brilliant with numbers or music is tone-deaf socially or linguistically. Also, many specialized cognitive skills, including recognizing faces, appear to be localized to specialized brain regions. Such evidence supports a modularity hypothesis, in which the mind is like a Swiss Army knife — a general-purpose tool with special-purpose devices.

[...] “That is, some cognitive abilities, like face recognition, are shaped by specialist genes rather than generalist genes.”

(Emphasis mine.)