Testing Intelligence

For more than a century the IQ test has been the crowning jewel in the quest to measure an individual’s intelligence, but recent research suggests that such tests should not be held in such high esteem.

To investigate the value of the IQ test, researchers carried out a project on behalf of the Daily Telegraph and New Scientist to ask more than 100,000 participants to complete 12 assessments that tested their abilities in; planning, reasoning, memory and attention. They discovered that rather than intelligence being reduced to a single factor, the relative success achieved in the assessment was influenced by three distinct elements - short-term memory, reasoning, and verbal ability.

Possibly most significant of all, they also found that just because you were good at one of these factors does not mean you are going to be good at either of the others.

Criticisms of IQ testing

These findings will warmly welcomed by a large body of scientists who have long claimed that traditional IQ tests are too simplistic. They believe the nature of intelligence is too complex to reduce to a single number produced as the result of a single exam.

There is much evidence that while IQ is a reasonably good predictor of academic success at school particularly within the sciences it is of much less value for indicating any achievements that may be made in the arts and creative subjects.

Perhaps these are perfectly reasonable criticisms. After all the current leading theories of intelligence have also moved away from a single General Intelligence factor (G), towards ideas of multiple intelligence  If we accept that they do not measure the totality of intelligence, do traditional IQ test still have a place?

What do IQ tests show?

There is a large body of evidence that shows whatever an IQ test is measuring, it is a good predictor of a wide range of outcomes for our lives. For example IQ tests predict job performance in almost every kind of work studies to date. The accuracy of the predictions understandably varies with the type of job, less in manual based industries and much stronger for professional careers, but in all cases a higher IQ suggests better job performance. This is suggested to be related to the ability to learn job-relevant skills and knowledge at a faster rate.

Charles Murray, co-author of The Bell Curve, also found that IQ measures are a good indicator of future incomes, and that this effect is independent of environmental considerations such as family background.

In addition to predicting higher incomes and better performance at work, other research has shown correlations between IQ and; being less likely to commit certain crimes, to being healthier and less likely to be overweight, and even to living longer.

What does an IQ test measure? 

IQ tests do measure certain core components that come under many models of intelligence. In particular an ability to rapidly store, process and retrieve information. Higher IQ scores are very strongly correlated with Working Memory Capacity, which suggests they may be measuring how much information we can hold in our heads and manipulate at one time.

Related to this ability to the capability information in our mind is the ability to identify patterns. This in turn hints at why they might be good predictors of success in the sciences, of mathematical ability and why a musical education appears to have a beneficial effect on IQ.

The key point that all the research agrees on, is that the time of IQ being the single measure of intelligence has passed, and to be useful it must now be considered as part of a wider range of cognitive tests that together can give a more complete picture of the reasoning and problem solving abilities of the human mind.

Dual N-Back Training

What is Dual N-back training?

The Dual N-back exercise is a cognitive training exercise that was deigned to stretch and develop working memory capacity (WMC).

The central idea is that you are presented with two simultaneous series to keep track of. Usually these are one series of letters spoken out loud, and another of spatial locations on a 3 by 3 grid. Your task is to identify when either the current letter or current location being presented is identical to one that was already presented a certain number of items ago.

This number is the ‘N’ in N-back.  When you start the N-back exercise, you will begin at the 2-back level. Every few seconds one of the 8 squares of the grid lights up (the centre square isn’t used) and at the same time a letter is spoken aloud. This will happen around 20 times and this is one complete set.

If during the set you correctly identify when either a letter or location is presented 2-back at least 80% of the time, the exercise increases N by 1. So you now move on to the 3-back level. If you manage to get 80% right at the 3-back level, N increases by 1 again to 4-back and so on. If you get less than 40% right at any level, N decreases by 1. If you score anywhere between 40% and 80% the next set will be at the same level again. 

Does Dual N-back training increase intelligence?

In 2008, Suzanne Jaeggi, a researcher from the University of Michigan, published a paper ,’Improving fluid intelligence with training on working memory ‘, which showed participants who had been performing daily 20 minute sessions of the Dual N-Back exercise displayed transferrable, dose-dependant increases in fluid intelligence (Gf).

So not only did their gains transfer over to a wide variety of other tests and measures of intelligence, but  the more they trained using the N-back exercise the larger their increases in measures of fluid intelligence.

Jaeggi, and her colleagues followed up this work with a further study published in 2010, ‘The relationship between n-back performance and matrix reasoning — implications for training and transfer’. This not only replicated the results showing Gf and WMC were both enhanced by training with the Dual N-back exercise, but also extended their findings by showing  that participants who used the single n-back variation also gained greater increases in Gf and WMC than controls.

A further study by Owen, McMillan, Laird and Bullmore; ‘N-back working memory paradigm: A meta-analysis of normative functional neuroimaging studies ‘, contained a meta-analysis of 24 studies that involved brain scans of participants while performing the N-back exercise.  This study showed the significant cognitive demand being placed on participants through the variety of brain regions that were consistently activated by performing this task.

These and many more studies demonstrating both the functional and anatomical changes that are induced by working memory training leave little room for doubt, Dual N-back training can increase intelligence.

Working Memory and Fluid Intelligence

What is Working Memory?

Working memory is an idea developed by cognitive scientists to describe how people are able to hold information relevant to a particular task in their mind, while having to simultaneously process information relating to other tasks and contend with additional distracting information.

Many fundamental cognitive abilities including; reading, reasoning, and problem solving all require input from working memory in order to function.

The relevant information is held in an accessible state, where you can continue to use and manipulate it. However because it must be continually held in this state it also has a limited capacity. Put another way; there is only so much information your mind can hold onto at one time, this limit is your Working Memory Capacity.

Working Memory and Fluid Intelligence

Throughout the 1990s many cognitive scientists believed that Working Memory Capacity and General Intelligence (g) were one and the same thing. Studies such as ‘Reasoning ability is (little more than) working-memory’, published in the journal ‘Intelligence’ by Kyllonen and Christal showed correlations between Working Memory and reasoning ability of between 80% and 90%. These and other similar results led most working in the field to conclude that even if working memory was not all there was to intelligence it was certainly the single most important factor.

What is Fluid Intelligence?

Along with Crystalized Intelligence, Fluid Intelligence is one of the two key factors which contribute to General Intelligence according to the Cattell & Spearman model of Intelligence. You can read more about the different theories of intelligence in the post What is Intelligence?

Most of the research that demonstrates the link between Working Memory and Intelligence has focused on testing reasoning abilities rather than acquired knowledge. Therefore it is actually a link between Working Memory and Fluid Intelligence that was being shown.

This aligns well with our common sense, when we are trying to measure intelligence we aren’t interested in pre-prepared strategies or relevant things we may just happen to know, but rather with how we cope with novel, unfamiliar problems.

More recent studies and analysis such as that done by Kane, Hambrick and Conway; ‘Working memory capacity and fluid intelligence are strongly related constructs’, have shown the original estimates of 80-90% correlations to be slightly over-optimistic.

When a battery of both simple and complex span working memory capacity tasks are included, Working Memory Capacity appears to accounts for around half of the variation in different individuals Fluid Intelligence.

Principles of Increasing Intelligence

Many exercises and techniques have been demonstrated to improve various aspects of cognitive performance, and some specific techniques which show transferable increases in intelligence have also been found. However most brain training exercises and games do not give any benefit beyond an improved ability to play that particular game.

If some exercises are successful at increasing intelligence while the majority are not, it is reasonable to conclude that simply engaging in any mental exercise isn’t sufficient, but rather there must be certain features or properties of these successful exercises which enable them to be effective.

What are the basic principles that form the foundations of successful exercises and techniques designed to increase intelligence? Can we extract out these principles in order to use them to design our own techniques, or directly integrate them into our lives? 

First Principle of Increasing Intelligence – Novelty

Our brains naturally seek novelty. The most rewarding experiences are those which take us out of comfort zone, providing new sensations, introducing us to new ideas and causing us to have new thoughts. This novelty also appears to be key for increasing intelligence.

When confronted with something new, your brain looks for ways to process the information more efficiently. It does this by seeking out patterns in the new activity i.e. trying to learn and understand what it is all about. All the while it is doing this the relevant regions of the brain show more activity and use up more energy. 

But the brain doesn’t like to work in this way, so it makes new, more direct neural connections allowing it to achieve the same results with less activity and using up less energy.

These new connections build on each other, increasing your overall neural activity. The more new activities you engage in, the more your synaptic network grows, creating more and more connections. In turn these connections allow for more associations in your mind, improving your ability to spot patterns, and to see where you can take ideas from one situation and apply them to another. This is a fundamental aspect of intelligent problem solving.

Second Principle of Increasing Intelligence – Difficulty

Our brains are naturally lazy. When you consider all the activities it has to be constantly engaged with in order to keep us functioning this might not seem obvious, but our brain will always take the easiest way out to get its job done. Since it is much easier to use existing neural pathways rather make new connections it will always do this wherever possible

To increase your intelligence, you need to force your brain to make these new connections by constantly challenging your brain. When something is difficult it means there is no ‘well trodden path’ in your neural network.  In order to work out a strategy or come up with a solution for a problem you find difficult, your brain will need to use a lot of energy to send signals round long winding neural paths to engage and pull information from separate brain regions.

Because it is lazy, your brain will soon realize it is a much easier option just to create new neural pathways that act as a shortcut rather than always having to go the long way round.

Creating more efficient pathways means you will be able to more easily solve complex problems. Things which used to be difficult, won’t seem so hard anymore. In order to keep creating these new more efficient neural pathways you will need to keep increasing the difficulty of the challenges you provide your brain. The idea is to aim for that state of slight discomfort you feel when you are just out of your depth.

Bringing the principles together

So what does this tell us about how to get the most from your brain training, well really it’s all about the individual. An exercise which might give one person’s brain a good workout, won’t do anything for someone else. So if you find Sudoku puzzles really difficult then they are a good brain training exercise, but  if you have got to the point where you can complete most puzzles in 5 minutes flat, they are no longer giving you any real cognitive benefit.

So the takeaway advice for using these principles to increase your intelligence; Look for new novel mental challenges which take you out of your comfort zone, but the soon as you feel comfortable its time to move on to a new challenge.

Can you increase intelligence?

 When answering this question we must first be careful to define just what it is we mean by intelligence. Different definitions and interpretations are discussed in an earlier post; What is Intelligence.  

After all under the most general definitions, it is clearly possible to improve intelligence. Why did we spend so much time at school if we were not able to improve our ability to learn and solve problems.

In the g factor model of intelligence, these kinds of abilities that it is intuitively obvious can be improved through study, are grouped together under Crystallized Intelligence (Gc). But what about the other key aspect, Fluid Intelligence (Gf), is it also possible for an individual to increase their natural ability to solve novel problems independent on any relevant knowledge or experience they may have.

For most of human history, in fact right up to the end of the twentieth century, it was widely believed throughout scientific and academic communities that it was impossible for someone to increase this kind of intelligence. This was due to the idea that the fundamental characteristics of fluid intelligence were determined by genetic factors.

Increasing evidence from the last two decades has been challenging that point of view, and today there is widespread support for the idea that it is possible to improve Gf.

 At the statistical level, concerning general populations, it appears it is happening naturally. Since the 1980s researchers have repeatedly measured the Flynn effect. Named after James Flynn following his 1987 publication, ‘Massive IQ gains in 14 nations: What IQ tests really measure’, the Flynn effect is the apparent gradually increase in a populations IQ, averaging around 3 IQ points per decade.  

There are many different explanations for this effect, from improved nutrition, more test aware children, to more stimulating environments. None of these explanation can conclusively demonstrate it alone is responsible, and it is entirely possible a more complex interaction of these and more factors combine to give improved IQ score. What is clear, is the effect is real; the increase is consistently seen in populations from all across the globe.  

For the time being let us leave the gradual statistical march of IQ scores, and turn our attention to the individual, as this may have a far greater significance on our understanding of intelligence. Is it possible for a person to make a noticeable improvement in their own intelligence?

Developments in neuroscience are repeatedly demonstrating the phenomenal plasticity of the human brain. Studies such as; ‘Neuroplasticity: Changes in grey matter induced by training’ by Draganski et al, have shown that mentally stimulating training induces selective structural changes within the brain. These changes in turn improve the mental processing associated with a particular skills or ability.

Are these structural changes in the brain useful for improving Gf?

The key in the search for a training regimen that would allow an individual to improve their intelligence is that any gains they make must be transferrable. A wide variety of ‘Brain Training’ games and activities have been put examined, and unfortunately the results have not been promising. Owen et al, summarised their finding in ‘Putting brain training to the test’, as “Although improvements were observed in every one of the cognitive tasks that were trained, no evidence was found for transfer effects to untrained tasks, even when those tasks were cognitively closely related”.

Although this finding is repeatedly reinforced for the vast majority of brain training exercises, it appears not all brain training games are created equal. In 2008, Suzanne Jaeggi, Martin Buschkuehl,

John Jonides, and Walter Perrig. published their study Improving fluid intelligence with training on working memory. They showed, using a particular cognitive training exercise known as Dual N-Back, that participants could through developing their working memory, achieve a lasting and transferrable increase in their fluid intelligence.

The findings of Jaeggi’s study have since been replicated. The success of these studies suggests a new approach; perhaps certain mental attributes like working memory formed a foundation to Gf. By improving these, individuals would also experience a knock on improvement in Gf.

More exercises that improve working memory have now been discovered, and further candidates for foundational attributes that underlie fluid intelligence have also been identified. Although the field is still in its infancy, there can now be little doubt, it is possible for people to increase their intelligence.

What is Intelligence?

Intelligence has been a remarkably difficult concept to pin down in any kind of robust and reliable way.  It often falls into that elusive category of ‘things we know exactly what they are until someone asks us for a definition’. Because of this there are many competing conceptions. The definition below is a synthesis of many of these different ideas.

Intelligence is our set of general problem solving skills. It includes cognitive abilities such as reasoning, identifying patterns and relationships, judgement, calculation, evaluation, and an ability to acquire new knowledge and skills.

An important aspect of most definitions seems to be that intelligence is not something related to our existing knowledge or particular skills we have developed but rather a general problem solving trait for novel situations. Perhaps this idea is best captured in the phrase; “Intelligence is what you do when you don’t know what to do”

Part of the problem in attempting to find a consensus on the definition of intelligence is there is no universally accepted theory of intelligence.  

Single or Multiple Intelligences?

One of the key questions in the search for a theory of intelligence is; ‘Do we possess a single attribute that could be defined as our intelligence, or are there in fact many entirely different types of intelligence?

If our intelligence can be expressed as a single attribute, can that attribute be divided into different aspects of intelligence? If so how are these different aspects related, and do they overlap? If, alternatively there are many different intelligences, how do we account for the high degree of correlation we find on many test scores that measure supposedly different cognitive skills?

Theories of Intelligence

There have been many different theories of intelligence put forward over the last century, but three in particular have been widely accepted within society and academic communities. 

General Intelligence

First proposed by Charles Spearman in 1904, was the theory of a General Intelligence factor (g). Accepting that there are different types of intelligence, Dr Spearman suggested they are all correlated, so if you score well on a test of one, you will likely score well on all the others too. This was because these different types were all related to the single General Intelligence factor (g).

This model as subsequently developed by Raymond Cattell who split the ‘g’ factor into two components Fluid Intelligence (Gf) and Crystalised Intelligence (Gc).

Fluid intelligence is identified as the ability to solve problems in novel situations, independent of any acquired knowledge. Key Gf skills are logical analysis, pattern and relationship recognition and adaptability.

Crystallized intelligence, on the other hand is the ability to use skills, knowledge, and experience. Key Gc skills are accessing memories, a wide general knowledge base and articulate vocabulary. 

Theory of Multiple intelligences

Howard Gardner a Harvard Psychologist, proposed this alternative model in his 1983 book Frames of Mind: The Theory of Multiple Intelligences.

Rather than a single general ‘intelligence’ there are eight distinct types of intelligence with no necessary correlation between them. 

This means just because an individual might perform well on a one test; say analytical intelligence for example, they could also perform badly on another, such as displaying poor emotional intelligence.

The eight types of intelligence under Gardner’s theory are: Spatial, Linguistic, Logical-mathematical, bodily-kinesthetic, musical, interpersonal, intrapersonal and naturalistic.

Since the original publication three further types have been suggested; existential, spiritual and moral intelligence. 

Triarchic Theory of Intelligence

Developed by Robert Sternberg in 1985, the Triarchic Theory of Intelligence takes a much broader view of intelligence. The starting point is that intelligence is defined as how well an individual deals with the environmental changes they experience throughout their lifespan.

Under the Triarchic model, intelligence are broken down into three subsets; analytical , creative and practical. These components are also known as; componential, experiential, and contextual

Analytical intelligence, refers to problem-solving abilities, Creative intelligence reflects the ability to deal with new situations using past experiences and current skills, and Practical intelligence is the ability to adapt to a changing environment. 

Conclusions

At present these and other competing theories of intelligence have yet to be reconciled into a single accepted theory. There is promise from some Neurobiological approaches such as P-Fit (Parieto-Frontal Integration Theory) proposed by Haier and Jung, that these different ideas may ultimately be shown to be complimentary descriptions.

Haier and Jung’s analysis of imaging studies attempting to locate brain regions involved in intelligence showed results are very similar regardless of the definition of intelligence used.

Even without a fully agreed theory, there are several features that all seem to share. These features equally cut to the heart of our intuitive idea of intelligence. Intelligence is a foundation for a wide variety of cognitive functions, skills and attributes. It is also the essence of problem solving, particularly where no prior knowledge or experience of the problem is available.