What Is Intelligence? What Is IQ?


What Is General Intelligence?

While people have different cognitive strengths and weaknesses, psychologists have found that there is a common component  called ‘general intelligence’ or ‘G. General intelligence  has been defined in many ways depending on the theoretical framework and context. I define intelligence as:

Your general intelligence is your ability to reason, problem solve, decide, learn & act efficiently & successfully in the pursuit of your valued goals.

There are different elements in this definition of intelligence: problem solving, reasoning, decision-making, learning and successful goal-pursuit. These all benefit from increased attentional focus & control and processing capacity in your brain.



1. Intelligence and Attentional Control

Intelligence is about your ability to control your attentional focus – your  ‘spotlight of attention’ –  in pursuit of your goals. Unintelligent people are easily distracted from their plans and goals; smart people have razer sharp focus when they need it. Unintelligent people do not know how to release their focus from a strategy that is not working; intelligent people are good at flexibly shifting their attentional focus.

Your attentional control is a function of what is called your working memory– the system in your pre-frontal lobe that is the  ‘mental workspace’ for for the information your brain processes while you are solving problems and making decisions.

Intelligent thought and action requires both focus and attentional flexibility – and the ability to overcome distractions and attend to the relevant information as well as the ability to switch attention between tasks when it is needed. This is called executive functioning.


Intelligence and Working Memory Capacity

2. Intelligence and Processing Capacity

Working memory not only enables us to focus on information, but it also enables us to process that information – to reason with it, find relationships and connections with it, while holding in mind different goals. The amount of data that can be held in mind in your ‘mental workspace’ and managed in this way is called working memory capacity. More intelligent people have a larger working memory capacity. Working memory capacity is correlated with a large number of general cognitive performance measures.



3. Intelligence and Problem Solving Ability

On almost all accounts, problem solving skills – your ability to solve unfamiliar problems using analytic and creative processes –  lies at the core of general intelligence.

Problems arise all the time, some abstract some concrete, and we differ in our ability to solve them. This problem solving ability reflects our intelligence, and smart people are quick to identify problems as positive challenges all around them.

  • ‘How to get all my work done in time for a deadline?’
  • ‘How to enforce privacy on Facebook?’
  • ‘How to sync my documents across computer devices?’
  • ‘How to solve this communication problem in my relationship’
  • ‘How to make that career transition?’
  • ‘How to lose weight?’
  • ‘How to raise my IQ and cognitive performance?’
  • ‘How to learn this skill set for work?’

What is problem solving ability?

Problem solving ability has been defined as:

“cognitive processing directed at achieving a goal when no solution method is obvious to the problem solver” (Mayer and Wittrock, 2006, p. 287).

Problem solving involves applying strategies to overcome obstacles to a goal – where a route to the solution is not immediately obvious. Problem solving depends on the skills and knowledge of the problem solver. What is a problem for one person (e.g. cropping an image) may be an automatic procedure not requiring thought for another.

More intelligent people have better problem solving ability above and beyond their baseline knowledge-base and skill-set. They have general-purpose problem solving strategies and skills that they can apply in any new situation.

Problem solving skills: Strategy skills

Cognitive strategies are general methods or rules-of-thumb that are used to solve problems efficiently – such as breaking a problem into smaller parts, or finding a related problem to help. Strategizing involves both applying rules and techniques, as well as  ‘meta-cognition’ – how to know when to apply a strategy and how to flexibly try different strategies to optimize your progress.

Problem solving skills: Decision making ability

Decision-making and problem solving go hand-in-hand. Applying strategies to solve our problems involves considering trade-offs such as risk vs reward,  time vs perfectionism, strategy x vs strategy y, continue-with-the-time-invested, or give-up-and-try-something-else, and so on.

And making complex decisions requires a large working memory capacity in order to hold in mind a number of factors that need to be weighed up simultaneously.

Smart people are good decision-makers in the pursuit of their valued goals.

Problem solving skills: Reasoning

At the very heart of general problem-solving skills is reasoning ability. All reasoning involves making inferences. An inference is drawing a conclusion from some information when the conclusion is not made explicit in this information. Reasoning is a way of generating new knowledge or actionables from the information you already have at hand.

Sometimes inference making is logical and certain – known as deductive reasoning. Sometimes it is probabilistic and based on patterns and generalizations – known as inductive reasoning. Either way, if you are good at it, you generate more knowledge or actionables.

More intelligent people are better at reasoning – both deductively and inductively. Human intelligence as a whole is traditionally defined by this capacity that other species like penguins largely lack!


Intelligence and Fast Learning

4. Intelligence and Fast Learning

The ability to learn efficiently from the problem-solving activity, and apply what you learn in the future skilfully, is also core to intelligence. Smart people are quick, efficient learners. They invest their attentional focus and problem solving strategies on tasks that they quickly assimilate as new long-term knowledge, building on their skill-set.

Research from cognitive psychology shows that the bench marks of intelligence we have looked at – working memory capacity,  attentional control, and the deliberate application and experimentation with strategies – results in much more efficient long-term learning.



What is IQ? IQ Definition

IQ or ‘intelligence quotient’ refers to a standardized measure of general intelligence on an IQ test.

IQ tests are the most reliable and valid type of psychometric test that psychologists make use of. Score on an IQ test can be used to predict performance in a wide range of activities outside the classroom. IQ tests are widely used in our society. Universities use IQ tests (e.g. SAT entrance exams) to select students, companies use IQ tests to screen applicants, and high IQ societies such as Mensa use IQ test scores as membership criteria. IQ scores have a distribution that looks like a bell curve.


IQ tests are designed so that the average IQ score is 100. In this graph, you can see that 68% of the population has an IQ score between 85 and 115. Around 2% of the population has an IQ greater than 130 which is a ‘very superior’ intelligence or ‘gifted’ intelligence. This is the IQ needed to become a member of Mensa. An IQ of 120 or more is considered ‘superior intelligence’.

Here is a table for what IQ scores mean:




Flynn, J.R. (2000) IQ trends over time: intelligence, race, and meritocracy. In K. Arrow, S. Bowles, & S. Durlauf (eds.), Meritocracy and economic inequality, Princeton, NJ, Princeton University Press 35-60

Mayer, R. E., & Wittrock, R. C. (2006). Problem solving. In P. A. Alexander & P. H. Winne (Eds.), Handbook of educational psychology(2nd ed., pp. 287–304). Mahwah, NJ: Erlbaum. (For a review, click here)

Morrison, A. & Chein, J. (2011). Does working memory training work? The promise and challenges of enhancing cognition by training working memory.  Psychonomic Bulletin & Review, Volume 18, Number 1, February 2011 , pp. 46-60(15)

Nisbett, R. E. (2010). Intelligence and How to Get It: Why Schools and Cultures Count. Norton. (Additional article here.)


Enter your email for direct delivery of new articles:


I am a cognitive scientist with a joint Ph.D in cognitive psychology and neuroscience from the Center of the Neural Basis of Cognition (Carnegie Mellon/Pittsburgh). At IQ Mindware we develop brain training interventions to increase IQ, critical thinking, decision making, creativity and executive functioning.