General Intelligence or g and it’s impact on education

The pursuit of intelligence in education is extremely important to us as educators. SAT’s GCSE’s, A Levels, Degrees, are all barometers of our pupil’s intelligence and thus, our performance as teachers. How much have our pupil’s progressed under our tutelage, how effective are we as professionals? There is an abundance of information about this on the web, on Twitter etc. and lots of stuff on multiple intelligence, Blooms, learning styles and much much more, all aimed at helping you to be able to improve the cognition of your students. But what do the scientists say REALLY works? Writing in 'New Scientist' magazine, Linda S. Gottfredson, professor of education at the University of Delaware and an expert in the social and cultural implications of intelligence, outlines what the current scientific understanding of intelligence is.

This article is my own summary transcript of her article.

g intelligence

The notion of ‘g’ (or general intelligence) prevails as the primary label by which scientists measure a persons ability to deal with cognitive complexity. This idea was first outlined by Charles Spearman in the early Twentieth Century and resulted in ferocious debate ever since. Spearman and his supporters on one side, who defend the power of his general factor of intelligence and on the other hand, supporters of the multiple intelligence abilities such as verbal, linguistic and spatial. Both sides eventually conceded that both had merit and in 1933 John B. Carroll published his three stratum theory, a pyramid in which the general intelligence ‘g’ factor rests on top, a middle layer comprised of ‘Broad abilities’; fluid intelligence, crystallised intelligence, processing speed, retrieval ability, cognitive speed, visual perception, auditory perception, memory an learning. A bottom level is composed of ‘Narrow abilities’ which are sixty four specialised aptitudes or skills that each relate to the broad abilities on the layer above. The Broad abilities are all composed mostly of g but each containing a different additive that boosts performance in the broad domains. The broad domains contribute to the sixty four narrow abilities, which are a complex composite of g and the broad domains.

This structure enables measurement of intelligence in multiple domains without compromising the notion of g intelligence. This multi-facetted approach, where all intelligence is underpinned by ‘g’ makes the notion of multiple intelligence implausible. However romantic it might seem to our inclusive education policies to attempt to assimilate different types of learners in our lessons, it appears that they don’t exist. All aspects of intelligence are driven by the g factor. This notion has been repeatedly tested and found to line up with diverse features of the brain, from relative size to processing speed and to defy cultural and species variance. Most cognitive variance comes from a variation in g.

But whilst the g factor as an indicator of intelligence is accepted, finding it in the brain is more difficult. Where is g in the brain and how do we get it? That is not certain but most likely, g comes from the actions of hundreds of genetic variants and environments which result in the brain’s overall efficiency. Higher g is useful for complex cognitive tasks such as school and for being associated with lower levels of damaging behaviour such as substance abuse, chronic illness and even premature death. It seems higher g is a real advantage, however it is not an indicator of emotional well-being, happiness or conscientiousness.

So is intelligence inherited?

The answer to this questions is that heritability of intelligence rises steadily with age, from thirty percent in preschool until by adulthood it is around eighty percent. This indicates that we cannot boost low intelligence, even into the average range, but we can add knowledge relative to the individual, to help them to know more and achieve more with the intelligence they have.

How does the home or school environment alter a person’s intelligence?

The answer is surprisingly little. Test on identical twins adopted into different homes with identical genes but with different environments show that IQ closely lines up with genetic similarity. In fact, these tests show that they answer IQ tests almost as if they were the same person and adoptees in the same household as if they were strangers. This indicates that most family environments are equally effective at nurturing intelligence regardless of where they grew up. This might be very frustrating for teachers trying to shape their pupils in particular ways and in any case, as people age, they tend to seek out the environments that suit their own cognitive complexity. But don’t despair teachers! These tests simply measure general intelligence, they don’t factor in aspects of education that define success in tests, such as method, discipline, rigour and learning approach. You can’t alter a person’s intelligence, however hard you try, but you can increase knowledge in the individual and create an environment conducive to more effective acquisition of the skills and habits of success.

Fluid intelligence versus crystallised intelligence

Some researchers distinguish between tests of fluid intelligence (gF); on-the-spot learning, reasoning and problem solving and crystallised intelligence (gC); broad cultural knowledge, prior intellect and vocabulary. During youth they rise in tandem but after that gF abilities decline whereas gC abilities remain constant. The implications of this are that the gC intellect buffers the decline of the gF fluid intelligence. Older people are generally less able to solve novel problems but compensate by being able to draw on their wisdom and experience. The most effective way of slowing down these losses in cognition is through physical exercise, which protect’s the brain by improving the body’s cardiovascular health. Also important is the avoidance of smoking, drinking and head injuries etc. Mental brain training has limited effect in boosting only specific skills.

Effects of environment and other factors on intelligence

Also of significant effect on our intellect is the natural variations in our cognitive ability caused by sleep deprivation, hunger, sickness etc. all of which cause significant fluctuations in our intellect over the course of a day or week. So when schools start too early, or when they fail to recognise the environmental needs of their pupils, these all affect performance. Of significant importance to educators is one that we have known for some time; that different levels of intelligence require different types of support. Educational and Military psychologists have shown people of below-average intelligence learn best when given concrete, step-by-step, hands on instruction with lots of practice, whereas people of above average intelligence learn best when allowed to structure their own learning. A one-size-fits-all approach stunts the learning of both types. Schools can get far more out of pupils by educating them to their personal potential. In fact cognitive overload is of particular concern in modern life. Medical trails have shown that there is a significant need to simplify the management of medication, especially in patients with a lower IQ. Schools might do well to heed this advice, when greater demand is being placed on pupils for higher exam results.

In the drive for increased success in our schools there is a thirst for a cognitive enhancer, a magic bullet that will provide the g factor for all, but this is a long way off. The most effective solution to date seems to be meditation. Evidence suggests that mindful meditation provides measurable cognitive improvement including attention and memory. In her final paragraph Linda addresses the ‘Flynn effect’; the idea that humanity is getting progressively smarter, since each successive generation is scoring on average 3 points higher per decade on IQ tests. This is unlikely a factor of cultural environment and the increasing complex world we live in since it is established that IQ is not affected by environment. It may be a side effect of increasingly better public health and growth. Also diversity of marriage and population may result in increased vigour of genes. More likely is that certain biologically rooted cognitive abilities related to IQ tests are improving. In short, we are getting better at passing the tests, rather than our whole cognitive ability improving.

From an article in New Scientist – 15 ideas you need to understand 2016,

by Professor Linda S. Gottfredson, University of Delaware, Newark.