Human Intelligence

Intelligence can be defined as a general mental ability for reasoning, problem solving, and learning. Because of its general nature, intelligence integrates cognitive functions such as perception, attention, memory, language, or planning. __ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3181994/

Definitions of intelligence tend to be broad, circular, and ambiguous. The more specific and falsifiable the claim, the more useful the definition in a scientific sense.

The first sentence of the definition above is so broad as to be almost meaningless. The second sentence begins to give a hint of scientific meaning. But as the authors proceed in their article, they start to provide some useful “meat” for readers to chew on.



Summary of above image: Occipital and temporal lobe areas process sensory information, pass it on to parietal lobe areas for abstraction and integration, then frontal lobe areas are called upon for hypothesis testing and problem solving, and finally the anterior cingulate is utilised for response selection and inhibition of alternate responses.

The authors of the above study from Dialogues in Clinical Neuroscience (2010) elaborated upon the close connection found between IQ and working memory, and various ways in which brain imaging findings correlate with psychometric IQ testing. As brain imaging improves in the future, functional intelligence of individuals might be better measured using brain imaging rather than psychometric testing.

What is the “Loss of Intelligence?”

Another way to look at intelligence is to approach it from a different direction. Instead of asking “what is intelligence?” for example, we can ask “what happens when intelligence is lost?” Consider the case of Alzheimer’s dementia, an increasingly common malady in ageing societies.

In Alzheimer’s disease, the most common form of dementia, there is disturbance of multiple higher cortical functions including memory, thinking, orientation, comprehension, calculation, learning capacity, language, and judgement. __ https://www.psychologytoday.com/us/blog/hide-and-seek/201811/what-is-intelligence

Dementia patients lose their facility to deal with changes in their environments. Unfamiliar challenges become more insurmountable with the progression of their disease. If we could take a dementia patient and “roll the clock back” to a time when the different parts of his brain functioned more normally, we might see the re-birth of intelligence before our very eyes.

By looking at basic building blocks of cognition, we might begin to explore intelligence from a different perspective from standard psychometric test designs.

Instead of starting with conventional psychometric tests, [the American psychologists Earl B. Hunt, Nancy Frost, and Clifford E. Lunneborg] began with tasks that experimental psychologists were using in their laboratories to study the basic phenomena of cognition, such as perception, learning, and memory . They showed that individual differences in these tasks, which had never before been taken seriously, were in fact related (although rather weakly) to patterns of individual differences in psychometric intelligence test scores. Their results suggested that the basic cognitive processes are the building blocks of intelligence. ___ https://www.britannica.com/science/human-intelligence-psychology/Cognitive-theories

The psychologists began testing how quickly their research subjects could comprehend basic differences in letter names and cases — and focused on comprehension times and “reaction times.”

Hunt, Frost, and Lunneborg concluded that verbally facile people are those who are able to absorb and then retrieve from memory large amounts of verbal information in short amounts of time. The time factor was the significant development in this research. __ https://www.britannica.com/science/human-intelligence-psychology/Cognitive-theories

Other psychologists who study cognition likewise began to focus on “reaction times” as proxies for cognitive skill, instead of standard psychometric testing.

The German-born British psychologist Hans Eysenck, for example, studied brain patterns and speed of response in people taking intelligence tests. __ https://www.britannica.com/science/human-intelligence-psychology/Cognitive-contextual-theories

Arthur Jensen has been one of the foremost investigators studying the correlation between reaction times and cognitive scores on standard psychometric tests.

The R T parameters derived from typical procedures cannot possibly measure knowl-edge, intellectual skills, or cultural background in any accepted meaning of these terms. Yet these RT parameters show signifi-cant correlations with scores on standard tests of mental ability and scholastic achievement and show considerable mean differences between criterion groups selected on such measures. __ AR Jensen

The “reaction time” approach to measuring cognitive skill is quite different from the psychometric approach. Instead, by testing the speed of some elementary building blocks of cognition one can gain a glimpse of general brain functioning on the cognitive level. Comparing speeds of inspection, comprehension, and reaction gives the researcher a means of comparing individuals and groups by their scores, using statistical methods.



Measuring Intelligence by Actual Outcomes

Mental Chronometry may prove eventually to be another replacement for psychometric tests in the search for valid measures of human intelligence.

Another way of measuring intelligence is to look at the different outcomes of achievement between individuals or groups. National GDP measures, for example, correlate quite well with national average IQ scores.



The direct correlation between average population IQ scores and national GDP measures is not a perfect correlation, but as a rough estimate the association is a provocative one that cannot be dismissed out of hand. In fact the relationship may be an exponential one.

National GDP may prove to be a type of “IQ test for national populations” when other relevant factors are adjusted in.

The gold standard for measuring human intelligence remains the validated IQ test, of which there are several. But better forms of brain imaging, mental chronometry, and sophisticated evoked response potential methods of testing brain function, may begin to provide more objective tests of human intelligence potential for both individuals and for group comparisons.

Intelligence is as intelligence does. For humans to solve problems they have created using one level of thinking, they must learn to raise their thinking to higher levels. This is not a challenge that can be pretended away, as the politically correct overlords of society would like us to do.

The Bell Curve by Murray and Herrnstein is a must-read on this topic.

General info on human intelligence from Wikipedia