Rational thinking and intelligence, do not confuse

Rational thinking and intelligence, do not confuse

19 April 2020 coaching 0

Intelligence and rational thinking, do not confuse.

Article C5s – APril 2020


Why do some people with high IQs fail while others with lower IQs are successful? You all know the answer now. Thanks to the contributions of Antonio R. Damasio (1994) and Daniel Goleman (1995). This is due to the emotional intelligence that can be stimulated and developed. Self-control, perseverance, motivation, respect for others are all qualities that make it possible to succeed.

But … that’s not enough.


Why are we surprised when smart people act foolishly? Smart people do foolish things all the time. Misjudgments and bad decisions by highly educated bankers, for example, brought us the financial crisis of 2008. Smart people do foolish things because intelligence is not the same as the capacity for rational thinking.

Personnalité problématique
Picture by  024-657-834 from Pixabay

Rational thinking

Intelligence is a matter of brain power and rational thinking is a matter of control. Some people who are intellectually capable do not bother much to engage in rational thinking and are inclined to trust their intuition.

Emotional intelligence, on the other hand, tends to demonstrate that human intelligence cannot be reduced to the mere intelligence quotient, disconnected from the interiority of the person.

However, the standard IQ and QE tests do not measure any of the main components of rationality: adaptive response, good judgment and good decision-making. We mistakenly call IQ, rational intelligence. But what an IQ test measures is our logic, our abstract reasoning, our speed of perception and discrimination, our ability to remember and retrieve information. What a QE test measures is our ability to perceive and regulate our emotions and to cope with those of others. But these tests do not measure our rationality, our ability to understand situations and make “good” decisions.

A few reminders on how our brain works

To put it simply, our brain can be divided into 3 entities. We are talking about the McLean’s 3 brains (triunic brain) presented in the 60s.

  • The rational brain (including the neocortex),
  • The limbic brain which manages our emotions but also among other things our memory,
  • And the reptilian brain which corresponds to our instinctive capacities. The ones that are required when a car is driving at you, and there is no time to think about understanding why the car is driving at you, or what emotions you are experiencing. You just have to move away as soon as possible.


But like the vision of the left and right hemisphere of the brain (the rational and the intuitive emotional), this vision of the 3 brains is now outdated. Neuroscience rather considers brain areas as sets in perpetual interaction.

A dual process model

Researchers estimate that our brain processes 11 million pieces of information per second through our senses. And our brain can only become aware of around 40 inputs per second. When at the same time we find ourselves rational, open-mind, our conscious part represents only a small part of what pushes us to act and to judge.

Our brain cannot consciously handle all of this information flow. He thus “created” an automatic mode, supported by the system 1.

The brain uses 2 different thinking systems to process information.

  • An intuitive and spontaneous system, the system 1,
  • And a deliberate and reasoned system, the system 2.

System 1 / System 2

Be careful, here too, as for the 3 brains, we must understand system 1 / system 2 as an allegory, which makes it easier to understand the functioning of our brain. Daniel Kahneman (Nobel 2002) presents it as two speeds of thought.

Fig 1.1 Dual Process Model (Kahneman 2012)
  • System 1 is the cognitive system that works automatically, involuntarily, intuitively, quickly and requires little effort. It is a reasoning system used by default. Among other things, it manages memory and emotions.


  • In contrast with System 1, System 2 is relatively slow and computationally expensive. Wrongly associated with the thinking ability, System 2 requires a certain concentration. He intervenes for the resolution of complex problems, thanks to his rather analytical approach. And anything new is a complex problem for our brain.


When system 1 encounters difficulties, it alerts system 2 to engage in more detailed and adapted analysis. But it doesn’t just alert. At the same time it suggests solutions. In fact system 1 constantly gives suggestions for system 2, impressions, intuitions, intentions and feelings. When everything goes well, system 2 adopts the suggestions of system 1 (Short cut).

Biases and heuristics

When we think about ourselves, we identify ourselves with system 2, the conscious self, which reasons, which has convictions, which makes choices and decides. But in practice, it is the automatic system 1 that most often decides.

Fortunately, the division of tasks between system 1 and 2 is extremely efficient. It minimizes efforts and optimizes performance. However system 1 has defaults. Defaults that he tends to systematically perform in certain situations. For example, he has a poor understanding of logic and statistics. We talk often in this case of biases.

The term “biases” refers to the systematic errors that people make in choosing actions and in estimating probabilities, and then the term “heuristic” refers to why people often makes these errors – because they use mental shortcuts (heuristics) to solve many problems.

For example, many people are willing to pay more for hamburger meat described as 94 % fat free than they would have been willing to pay for the same meat described as containing 6% fat. People respond differently depending on different wordings of an equivalent problem.

Toward a tripartite structure model

A simple task of letter pronunciation might entail encoding the letter, storing it in short-term memory, comparing it with information stored in long-term memory, and, if a match occurs, making a response decision and then executing a motor response. We will refer to this level of analysis as the “algorithmic level”.

But if we turn to an analysis of goals, desires and beliefs to understand a situation, we will refer to the “reflective mind”.

Fig 1.2 Tripartite Structure Model (Stanovich 2016)

Thus, as long as variation in thinking dispositions is not perfectly correlated with variation in fluid intelligence, there is a statistical possibility that rationality and intelligence diverge. In fact, substantial empirical evidence indicates that individual differences in thinking dispositions and intelligence are far from perfectly correlated.

For example, one does not maximize the deliberativeness dimension because such a person might get lost in interminable pondering and never make a decision.

To put it simply, the concept of rationality encompasses 2 things: thinking dispositions and algorithmic-level capacity.

Thinking Dispositions (cognitive style)

Thinking dispositions concern the objectives and the hierarchy of objectives. They are based on our beliefs, our needs (need for cognition, need to evaluate, etc.) and our motivations. This translates into our tendency or not, to gather information before making a decision, or our tendency to seek several points of view before reaching a conclusion. It is our tendency to think about the future and its consequences before taking action. All these cognitive abilities are not assessed by an intelligence test such as IQ or EQ.

However, these thinking dispositions are well taken into account in our decision-making.

Take in consideration that these thinking dispositions are individual, specific to each individual. Thus we will speak of cognitive style.

Miserly processing

In the center of Kahneman’s theory, as you have understood, is the idea that we must distinguish between rationality and intelligence. No matter how intelligent we are, we still have to think, realize and decide to use our cognitive capacities in an optimal way.

In fact people are cognitive misers because their basic tendency is to default to processing mechanisms of low computational expense.

Intelligence tests do not focus on the autonomous Type 1 processing of the brain. However, the latter process is the most used in everyday life. IQ tests also do not capture knowledge related to rational action and the reflective mind.

The skills of judgment and decision making are cognitive skills that are the foundation of rational thought and action, and they are missing from intelligence tests (IQ …).

The rational thinking

Psychologists have studied the main reasoning errors that make people less rational. They identified the tendency:

  • to evaluate probabilities inconsistently,
  • to trust too much ready-made knowledge,
  • and to ignore alternative hypotheses,
  • to evaluate the data available with a bias in its own favor,
  • to display inconsistent preferences due to the framing effect,
  • and to give excessive importance to short-term profit despite a long-term well-being,
  • to decide according to a context which has nothing to do with it,
  • etc.

All these forms of error in rational thinking and decision-making are very poorly correlated with intelligence – in other words, it is difficult to measure individual differences in the field of rational thinking with IQ tests. Recent advances in the cognitive sciences, which are part of rational thinking, now allow these facets of cognitive ability to be measured.

Toward a test of rational thinking (RQ)

The rational quotient (RQ)

Rational thinking, like intelligence, is a measurable cognitive competence.

Drawing on theoretical work and empirical research from the last 2 decades, Stanovich and al  presented the first assessment of rational thinking analogous to the IQ test. They called it the CART (Comprehensive Assessment of Rational thinking). It has been meticulously tested with over 4,000 participants.

But if this test is suitable for research and can serve as a gold standard for measuring rationality, it is not suitable for daily use. It requires between 1h30 (short version) and 3 hours to be completed.

Our consulting company, C5s, will present a 45-minute functional version of this test in French and English. This is a version suitable for personal development or recruitment. However before this functional version can be fully operational, we need to perform its calibration on a consistant population. What we expect during the year 2020. Waiting for that, feel free to try our prototype.

Cognitive capacity and rational thinking


Kahneman studied the decision-making process, which makes our thoughts and actions rational or not. He explored how we make choices and weigh the odds. He highlighted the basic errors (cognitive bias) commonly encountered when making a decision.

In parallel, our thinking dispositions, which concerns our objectives and their hierarchy, as well as our beliefs and our needs, directly impact our decision-making (Tripartite model).

To be rational means to adopt the appropriate objectives and to act accordingly. It means achieving the goals we set for ourselves by implementing the best means to achieve them. Research in Keith Stanovich’s laboratory shows that there are systematic individual differences between judgment and decision-making capacity.


The test of Rational Quotient (RQ)

By constructing a formal assessment device, the RQ measures the skills that IQ testing has largely ignored. The RQ explicitly taps knowledge related to rational action and belief, and taps the reflective mind that an IQ test does not or few.

It is true that heuristics and biases problems seem more hostile than typical IQ test problem. IQ tests assess the algorithmic power of the mind in benign environments. But IQ tests do not pick up these hostile aspects of the cognitive environment of modernity. Modernity increasingly requires décontextualisation and flexibility.

Access to the RQ, as shapped by K. Stanovich, is under copyright material. There is no free access.

Sources :

Thinking, fast and slow (D. Kahneman – 2012)

The Rationality Quotient : toward a test of rational thinking (Keith Stanovich – 2016)


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