what does IQ stand for

The exact definition of intelligence is a debatable, intellectual pursuit. However, the generally accepted definition (i.e., the working definition) of intelligence is as follows – 

Intelligence is one’s ability to gain knowledge and, one’s ability to use this knowledge to problem solve or to meet an objective. 

In layman’s terms, intelligence refers to how smart or clever an individual is. 

The problem with intelligence is that it is an abstract concept. As social scientists, psychologists, and medical personnel began trying to quantify intelligence, they soon realized that it was a bit like nailing Jell-O. Despite the remarkable challenge they faced, they continued to design ways in which to measure an individual’s intelligence - objectively, and accurately. 

In 1912, the psychologist William Stern created the term IQ. The catchphrase Intelligence Quotient (IQ) is derived from the German concept known as intelligenzquotient – a scoring method developed and used by William Stern when he was a professor. 

More than 100 years later, the concept of the Intelligence Quotient remains an ongoing debate; however, the concept (and what it represents) is readily accepted and used by many industries to evaluate potential students or employees, across a number of disciplines. A partial list of how an IQ test is used includes an academic appointment, job performance and evaluating the level of someone’s intellectual disability. 

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What is an Intelligence Quotient (IQ)?

An Intelligence Quotient is a mathematical measurement that is calculated from the results of an IQ test. The IQ score is a measurement of your intelligence, expressed as a number. However, it is important to note that an IQ score is based on data derived from abstract concepts, so an IQ score can only represent an estimate of one’s intelligence. 

Your final IQ score is the decisive evaluative calculation of how you performed on the IQ test in terms of problem-solving and logical reasoning.

IQ Test Preparation

An upcoming IQ test date is likely to be chock full of anticipatory anxiety. And while it is nearly impossible to study for an IQ test, there are practical ways to improve your chances of optimizing your score. The smartest way to maximize the IQ testing experience is to become familiar with the questions on a typical IQ test, testing environment, and the exam rules. 

Take advantage of the many free online IQ tests (and IQ scoring explanations) that offer the opportunity to grow familiar with - 

  • How the IQ test is formatted. 
  • The content of previously used IQ test questions.
  • A working baseline score to judge your future progress.
  • The unusual scoring methodology.

IQ Tests Currently in Use

While there are a variety of Intelligent Quotient examinations given to today’s test-takers, the most commonplace IQ tests include –

  • The Standford-Binet Intelligence Scales. 
  • The Wechsler Adult Intelligence Scale (WAIS).  

The Stanford-Binet Intelligence Scale 

The Stanford-Binet Intelligence Scale IQ test is most widely known as it is used to assess intelligence in young adults and children throughout the public school system. Although, the administrators noted that this exam could be taken by anyone aged 2 through 85. 

The Stanford-Binet Intelligence Scale was first developed in France more than 100 years ago by Alfred Binet, a psychologist working in concert with the French government to evaluate each child’s intelligence, so each child receives the educational support that is needed.  At that time, it was known as the Binet-Simon Scale, as Binet’s student Theodore Simon and he were partners in developing the finalized version of the intelligence scale.

When the Binet-Simon scale (and its associated test) was translated to English, the United States public school systems began testing children to gauge a student’s intellectual abilities, and the psychiatric community began using it as a diagnostic tool to identify mental health issues. In fact, the US military, during WWI, tested each new cadet. 

Several years later, the educational psychologist Lewis Terman modified the original Binet-Simon Scale as a Stanford University professor studying the genius in gifted individuals, especially children. By 1916, the newly named Stanford-Binet Intelligence Scale was officially adopted as the United States’ standard IQ test.  

IQ tests, like the Stanford-Binet Intelligence Scales or the Wechsler Adult Intelligence Scale (WAIS-IV), are made up of at least one hundred questions and can take an hour or more to complete. 

The following table offers a visual explanation of how the Stanford-Binet is organized -

  stanford binet organization

Source: Emporia.edu


The Reliability of the Stanford-Binet IQ Exam

The Stanford-Binet IQ examination has undergone a litany of revisions, but has been successfully validated by several scientifically-backed studies over the past century or so. The reality is that human intelligence is unreasonably difficult to measure, so each IQ test version bumps up against issues that need addressing. However, after one hundred years in use, the Stanford-Binet test generates results that are deemed accurate by the educational community and other industries.

The Wechsler Adult Intelligence Scale (WAIS)     

The American psychologist, David Wechsler, created the Wechsler Adult Intelligence Scale (WAIS) in the mid-1950s. It is noted, however, that the precursor to the now widely used Wechsler Adult intelligence Scale (WAIS - IV) was called the Wechsler-Bellevue Intelligence Scale (WBIS). The WAIS' response to the WAIS was overwhelming and by the 1960s, the WAIS IQ test held the distinction as being the most popular IQ test in use. The latest version of the Wechsler Adult Intelligence Scale is known as WAIS-IV.

The fundamental difference between the Stanford-Binet and the WAIS is that the WAIS seeks to assess the intelligence of adults, where the Stanford-Binet was designed for testing children and young adults. 

David Wechsler was interested in evaluating a test-taker's knowledge acquisition capabilities, their intelligence, and comprehensive understanding because it was his belief that a person's intelligence was comprised of interrelated components that could be, if isolated, accurately measured. Wechsler also recognized that the Stanford-Binet test was geared towards children and not adults. 

The WAIS is the most often administered to young adults (i.e. teenagers) and adults between the ages of 16 and 90.  

Note: IQ tests are substantially different than personality tests.

IQ Classifications

Each of the IQ scoring scales for the Stanford-Binet and the Wechsler IQ Tests interprets test results against other test-takers (in similar age categories) to determine where your score falls along the IQ scale spectrum. The basic categories include –

  • Above Average
  • Average 
  • Below Average

Neither the Stanford-Binet nor the Wechsler IQ test choose to label their IQ categories as Mental Deficiency, Normal, or Genius because –

  • The mere implication of these words is often hurtful, and therefore unnecessary. They certainly do nothing to enhance IQ scoring charts. 
  • The use of more neutral words easily delineates scoring divisions without the delivery of hurtful labels genius, or mentally flawed.
  • It is impossible to define what ‘normal’ is in terms of IQ testing, and for most other matters.

The IQ as a Mathematical Concept

By itself, an IQ score has no real meaning. It’s meaning is only created when used as a comparative tool against a specifically selected ‘sample’ population. 

Your IQ score is a statistical placement based on where your score falls in direct relation to the scores generated by other test takers that conform to the general population that best describes you, the test taker. 

IQ scoring uses a standard bell curve to denote where a test-taker’s test results fall in relation to the test-taker’s defined population – 


IQ Bell Curve 

 Source: Chris53516 at English Wikipedia [Public domain], via Wikimedia Commons


The IQ score chart, shown above. visually represents what is known as a normal distribution. The vertical axis contains the number of people who have earned a particular score. The horizontal axis is the defined distribution of all the possible IQ score results.

The IQ grading curve is designed to have an average IQ score of 100. This simply means that –

  • A score above 100 indicates the test-taker has above average intelligence.  
  • A score below 100 indicates the test-taker has below-average intelligence.

Perhaps the most confusing part of IQ scoring is the fact that most tests calculate a grade by comparing the correct number of answers to the total number of questions on a test. So, if you score 77 questions correctly on a 100-question test, your final score would be 77%. However, the IQ scoring model differs.

IQ Scoring is a bit more complicated. Instead of being scored against the test, an IQ test-taker’s score is ranked against other IQ test-takers in a ‘specifically defined population’ using a weighted scale. The purpose of using a weighted-scale is to introduce objectivity into the IQ’s testing results. Ultimately, a weighted scoring method allows for objectivity to overcome an IQ’s potential subjective results. 

What Is The Highest IQ Test Score?

For those who are curious as to who has scored the highest IQ score EVER, the Guinness Book of Records claims that Marilyn vos Savant scored 228! What is even more remarkable is the fact that Ms. Vos Savant achieved this score when she took an IQ test at age 10!

If you take a glance at the standard bell curve graphic above, you will notice that a score of 228 does not even make the charts. In fact, only ½ of 1% even score above 140. 

The Take - Away

Testing and educational scientists have shown the IQ test to be a solid predictor of a test takers’ -

  • Performance at work.
  • Health.
  • Inclination towards a criminal lifestyle.
  • Life Expectancy. 
  • Socio-economic placement in society. 

The IQ test is imperfect because it is man-made, but overall it helps determine many important issues related to life’s goals, expectations, and objectives. 


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