Does IQ matter?

This post questions the relevance of intelligence (IQ) tests in the light of evidence that raises questions on their reliability and validity. Other types of intelligence are explored.

Key points

  • Average IQ score increase over time
  • The belief in multiple forms of intelligence is increasing
  • High IQ does not necessarily lead to success in everyday tasks
  • IQ test results can be dramatically improved through offering short-term incentives

Questions to first consider

  1. Have you ever taken an IQ test?
  2. If you were give the chance right now, would you take one? Why?
  3. Do you believe that successful people have a higher than average IQ?
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The correct answer is at the end of this post.


There is a widely held belief, especially in educational environments, that a person’s academic success, (and ultimately job performance and income) can be predicted by their score on a standard intelligence (IQ) test.For this reason, they are routinely being conducted in schools to make decisions on student placement.

This post will explore their relevance in the light of new evidence and begin to examine other factors that play a part in determining success, both in education and in other areas of life.

 A brief history

Intelligence testing has been carried out for over 100 years. Psychologist Alfred Binet developed the first tests of this kind in the early 1900’s. His early tests were focused mainly on verbal skills and were designed to measure a child’s mental age based on language ability.

These early test have been refined and modified over the years and more recent tests also include attention, memory and problem-solving skills. These types of general intelligence tests are widely used as an educational tool but their validity is dependent to a large extent on the scores remaining constant over time and being unaffected by external factors.

Recent research has shown that an IQ test score can be improved to a small extent at an early age, but becomes more fixed as we age. By the time a student enters university, their IQ as measured in these standard tests, is unlikely to change. Interestingly however, since the early 1900’s average scores in IQ tests have been rising at the rate of 3 IQ points per decade in most parts of the world.

Tests in doubt

Questions still remain on the validity of these tests and interestingly, Binet himself believed that intelligence was far too broad a concept to be measured by a single test (Kamin 1995).

Some of the current areas of contention are:

  • Is intelligence a single ability, or does it involve an assortment of multiple skills and abilities?
  • Is intelligence inherited, or does the environment play a larger role?
  • Are intelligence tests biased (for example towards people with a higher level of education or social background)?
  • What do intelligence scores actually predict, if anything?


The BBC video below titled ‘What makes us smart’ explores some of the questions above and come up with some surprising answers. First watch the video then take a short quiz.


Now take the quiz. To assist you, here is a description of the seven participants:

  • Susan – chess grand master
  • Garry – jet fighter pilot
  • Nathan – IQ specialist and Wall Street trader
  • Seth – quantum physicist
  • Stella – artist
  • Alex – musician
  • Bonnie – dramatist, author and critic

Click below to take the quiz

[WpProQuiz 4]

Multiple Intelligences and emotional intelligence

During the above video, reference was made to the theories of Howard Gardner on multiple intelligences. This concept is now being widely used in many schools in the design of lessons.


Click on the link below to take a free quiz that identifies your areas of strength according to this theory:

Multiple Intelligence Test

You can also take a free emotional intelligence (EQ) test by clicking on the link below:

Emotional Intelligence Test

A further challenge to IQ test validity

It is clear then that the validity of IQ tests is being challenged by those who believe that they do not measure all types of intelligence. A further challenge to their validity has come from research that identifies a range of other factors that affect achievement and success.

In one such study, first conducted in the late 1960’s, 79 children aged between 5 and 7, were given standard IQ tests. They were then divided into a control and experimental group, and 7 weeks later similar IQ test were conducted. This time however, children in the experimental group were told they would be given one M&M for every correct answer. The result was that the IQ score of the M&M group rose by an average of 12 points.

This clearly shows that IQ tests do not measure something permanent, but rather that results can vary depending on other factors – in this case short-term motivation.

A subsequent test found that the most significant impact of this effect was amongst students in the lower IQ range. It was found that offering M&M’s as an incentive had the effect of moving this lower group, on average, into the middle range.

 Where to from here?

In future posts we will continue examining other factors that can play a part in student academic success?

(The correct answer is d)


Kamin, L. J. (1995). The pioneers of IQ testing. In Ressell Jacoby & Naomi Glauberman (Eds.), The Bell Curve Debate: History, Documents, Opinions. New York: Times Books


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