What is intelligence? It sounds pretty simple right, but in fact researchers and psychologists have grappled with a sole definition of intelligence for as long as can one can remember.

Most concepts and ideas around intelligence can be described as the ability to learn from experiences, recognise problems and solve problems. Some psychologists believe that intelligence is mostly inherited whereas others believe that intelligence is mostly influenced by the environment.

History of Intelligence

Sir Francis Galton, the cousin of Charles Darwin, in the late 1800s was one of the first people to study intelligence.

Galton was primarily interested in gifted people, individuals with a superior thought process than the average person. He set up a lab to measure reaction times and other physical abilities to test his theory that intelligence is a mental ability that is a product of biological evolution.

According to Charlotte Ruhl of Simply Psychology, “Galton’s study of intelligence in the laboratory setting and his theorization of the hereditability of intelligence paved the way for decades of future research and debate in this field.”

Ever wondered where the term intelligent quotient (IQ) stems from? Well it was first used by German psychologist William Stern. The theory was then later developed by Alfred Binet and Alfred was the first to test intelligence by helping a French school identify schoolchildren who needed extra academic assistance.

Since the term IQ was first used there have been many controversies and debates surrounding how intelligence is measured. However, the test has been a great tool that has led to the development of many tests of skills and aptitudes.

Testing Intelligence

One of the most common ways of testing intelligence is the Stanford-Binet Scale. It is an assessment which measures intelligence in five sets, namely cognitive ability, fluid reasoning, knowledge, quantitative reasoning, visual-spatial processing and working memory.

This test, referred to as IQ, uses a single number to indicate an individual’s score.
● Average intelligence score is from 90 -109
● Score from 110 – 119 is higher than average
● Scores from 120 – 129 are superior scores
● Very superior scores are anything over 130

How to calculate IQ:

According to Charlotte of Simply Psychology, a person’s mental age is divided by his or her actual age and then multiplied by 100. So let’s say your mental age is 17 and so is your actual age then you would have an IQ of 100, which is the average. Or let’s say your mental age is 23 and your age is 20 then you would have an IQ of 115.

According to Nigel Holt and co-authors in the book, Psychology: The Science of Mind and Behaviour, “Today’s tests (IQ) no longer use the concept of mental age. Although the concept works pretty well for children… Stern’s quotient is less useful for adults.” Nigel Holt further explains that modern day IQ scores are not a quotient at all, but based on a person’s performance compared to people in the same age group.

Multiple Theory Intelligence

Howard Gardner, a Harvard psychologist, has a theory that consists of multiple intelligence. He believed that intelligence based on the IQ test didn’t accurately portray a person’s abilities. So Gardner developed eight of his own intelligence theories.

Bodily-kinaesthetic intelligence: This is the ability of controlling your body movement

Interpersonal intelligence: The ability to understand and relate well to others

Intrapersonal intelligence: In essence this is the intelligence in accepting who you are; getting to know and understanding your feelings, values and beliefs

Logical-mathematical intelligence: The ability to think in an abstract and conceptual way, and also to decipher logical and numerical patterns

Musical intelligence: The ability to create rhythm, pitch and timbre

Naturalistic intelligence: Being able to recognise and categorise animals, plants and other objects in nature

Verbal-linguistics intelligence: Strong verbal skills and the ability to use language well

Visual spatial intelligence: Thinking using images and pictures, and to visualise accurately and abstractly

Emotional Intelligence

Another form of intelligence is emotional intelligence or EQ. According to Psychology Today, “Emotional intelligence refers to the ability to identify and manage one’s own emotions, as well as the emotions of others.”

There is no test or method to measure emotional intelligence, but an emotionally intelligent person can be described as being highly aware of their emotional state, whether that be positive or negative and they are able to manage their emotions in a healthy manner.

It is said that emotionally intelligent individuals tend to make great leaders as they can understand others at a deeper level.

Intelligence is a tricky business and something that is highly debatable. Should we even try to measure intelligence? There are a whole host of factors to consider. Humans are intelligent in different aspects, in different ways and spaces. It’s up to you to determine where you best thrive.


If you enjoyed this, read here to find out why Africans are born Mathematicians.

Tell us: Do you think intelligence should be measured? And if so, in what way?