What is an IQ test and how does it work?
April 15, by Marissa Edinger

German Psychologist, William Stern, coined the term IQ, short for Intelligence Quotient, which is referred to as a score that’s derived from a standardized test.

The purpose of an IQ test is to measure the mental abilities of an individual. Those with a high IQ scores are considered to be smarter than the average. These scores can also be used to compare two or more people on intelligence.

A reference tool for the evaluation of intellectual potential in 2018

Here is a free IQ test consisting in 40 questions of increasing difficulty level. The candidate must choose from a range of symbols to find the one which completes the set. The challenge is to grasp the relevance of the symbols without context and to understand the relationship between them.

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Disclaimer: this IQ test is particularly challenging because it assesses the top 25% of the cognitive capacity range. Don't give up!

The first IQ test

The first IQ test was conducted way back in 1904. French government officials requested Alfred Binet, a french psychologist, to help them find out the students that struggled in school so that they could be helped.

Alfred, along with his colleague, Theodore Simon, prepared a test with different questions. These questions were from different walks of life, but most were related to practical matters like problem-solving, attention, and memory.

Since these topics were not typically taught to students in schools, both Alfred and Simon agreed that this was the best way to filter out students.

The test turned out to be a success as some kids were able to answer questions beyond their age. Here’s where the concept of mental age came into being.

This was the first IQ test conducted by Alfred and Simon. However, the test went through several changes as different experts gave their own inputs on the concept.

Let’s get to know more about today’s IQ tests in detail.

What is an IQ test?

An IQ test is a test conducted to determine the mental abilities of an individual. This test consists of several more or less complex questions that need to be solved within a specified time period. The result is given out in the form of a score. Higher the score, higher the intelligence and vice versa.

These tests are used in different fields to judge a person’s skills. In fact, many organizations require applicants to submit their scores when hiring new candidates.

There are various kinds of IQ tests though and not all of them measure the same mental capacities of a person. I’ll get to the different kinds of IQ tests later in this article.

How does it work?

IQ is a numerical range which helps to figure out how intelligent a person is. According to reports, the highest possible score on an IQ test is around 200, however many individuals have scored above this figure and they are all considered to be some of the smartest minds in the world.

Generally, a score of 100 is considered to be average. Anything below 100 is considered to be low intelligence and a score above 130 is considered to be very good. Moreover, a score below 70 points is dangerous because it points to a learning disability.

The main goal of an IQ test is not to test you individually but to compare you and others at the same age group.

Things tested in an IQ test

An IQ test isn’t based on just one or two fields, there are a lot of factors that make up an IQ test. The test is designed to cover different subjects and topics. These include:

  • Crystallized Intelligence – This involves measuring how good an individual is at making use of specific knowledge and at extracting information from the past.
  • Fluid Intelligence (Problem Solving) – It involves identifying patterns, using mind power and logic to come up with solutions to problems.
  • Verbal Knowledge – An individual’s vocabulary is also measured in an IQ test. This includes vocabulary reasoning, extensiveness of vocabulary an individual can use, verbal memory etc.
  • Processing Speed – An IQ test isn’t just about using information, it’s also about how fast a person is in processing the information. IQ tests are timed and the scores heavily depend on how quickly a person solves the test.
  • Spatial Intelligence – One of the most important parts of an IQ test is the testing of spatial intelligence. This part of the test determines how good a person is at recognizing shapes and 3-dimensional images. Many experts believe that this is one of the most difficult parts of the test.

According to scientists, the right side of our brain is responsible for triggering spatial capabilities such as solving puzzles, remembering maps etc. Individuals with good spatial intelligence are said to become good engineers.

Combining all these factors and conducting a test gives an overview of how all rounded a person’s intelligence is and that’s what an IQ test is all about. It helps people know where they stand in terms of intelligence. Moreover, it can also help individuals choose a career as the test can help them understand where they excel.

What are the different types of IQ tests?

There are many types of IQ tests being taken around the globe with a mutual aim, to measure the intelligence of a person. While they all aim to measure the same thing, the methods differ. Let’s get to know more about these tests in detail:

Stanford-Binet Test

The first ever IQ test was the Stanford-Binet test. This IQ test involves measuring the intelligence of a person based on 5 factors.

  1. Knowledge
  2. Quantitative reasoning
  3. Fluid reasoning
  4. Working memory
  5. Spatial-visual processing

Once all these factors are tested, the weightage of each individual depart is measured and combined together to give a final outcome, that is, the IQ score.

This test is one of the most dependable and reliable IQ tests since it is the first ever test introduced and has gone through many revisions.

WAIS – The Wechsler Adult Intelligence Scale

This IQ test was designed by David Wechsler in 1955 who thought that the Stanford-Binet IQ test had limitations to measure intelligence.

According to him, the Stanford-Binet test was designed for children only and was not suitable for adults. This is why he came up with his own test.

The Binet test was more like a self test in the early days because the result was determined by dividing the mental age of the person with their chronological age. Oh the other hand, the WAIS test involved comparing the test score among people of same age. Later on, the modern Binet test also adopted this way of determining results.

Five factors that are being tested on this test:

  1. Visual-spatial Processing – recognition of both patterns and spatial relationships and the ability to recognize the whole from its constituent parts.
  2. Knowledge – someone’s accumulated stock of general information that has been committed to long-term memory.
  3. Working Memory – the multiple processes that capture, sort and transform information in a person’s short-term memory.
  4. Quantitative Reasoning – a person’s numeracy.
  5. Fluid Reasoning – the ability to solve problems in which no prior knowledge is require.

Woodcock–Johnson Tests of Cognitive Abilities (WJ IV)

Designed by Richard Woodcock and Mary E. Bonner Johnson, this test is meant to be for people of all age groups, including children as young as two years.

In this test, a number of mental capabilities are tested including:

  1. Fluid intelligence – Quantitative Reasoning, Induction, General Sequential Reasoning
  2. Spatial-visual intelligence – Mental rotation, Visualization, Spatial relations, Visual memory
  3. Short term memory – Working Memory, Memory span
  4. Auditory processing – Phonetic coding, Word fluency
  5. Processing speed – Perceptual speed
  6. Long term retrieval – Ideational Fluency, Associative memory
  7. Crystallized intelligence – General Information, Listening Ability, Language Development & Lexical Knowledge

Raven’s Progressive Matrices

Mainly used in educational settings, this IQ test was developed in 1936 by John C. Raven. It is concerned with assessing cognitive abilities of an individual and is a non-verbal test usually taken in groups.

The test is perfect for people aged 5 or more and consists of 60 questions arranged specifically. The arrangement of questions is also used to judge a person’s skills.

In this test, questions are arranged in a matrix (2×2, 3×3, 4×4 or 6×6) each having different images with one image missing. The respondents are required to identify the missing factor.

The factors tested in this test are:

  1. Clear-thinking
  2. Advanced observation
  3. Problem solving
  4. Learning ability
  5. Abstract reasoning