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Inventors -

A psychologist named Alfred Binet and his partner Théodore Simon created a test to help children who were struggling in school.

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Student evaluation -

The purpose was to determine if the child needed specialized attention. Their method would become the basis for the IQ test.

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Intelligence -

During this period in history, researchers believed that abilities such as verbal reasoning, memory, and visual-spatial skills reflected a person's general intelligence.

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Scores -

Binet and Simon designed a series of tests that evaluated each of these abilities and combined the results into a single score.

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Intelligence Quotient -

The result reflected how well the child performed compared to an average child of their age. It was called the "Intelligence Quotient," or "IQ."

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Modern IQ scores -

Today, a score of 100 indicates the average of a sample population. Currently, 68% of the world's population score within 15 points of 100.

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Defining intelligence -

However, there has never been a consensus on how to define general intelligence.

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Applications of the test -

Sadly, this left a lot of room for interpretation and the test model was applied in troubling ways, often reflecting biased assumptions about the nature of intelligence.

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Flawed ideologies -

In many cases, it was used to sort people on the basis of some very flawed ideologies.

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US military -

It was first used by the US military during WWII. They used it as an aptitude test to sort recruits into different positions based on their perceived intelligence.

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US military -

Those who scored highest would be considered for officer training, and would naturally find themselves in safer roles.

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Eugenics -

There was a common belief at this time that undesirable genetic traits should be controlled through selective breeding.

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Eugenics -

This idea was even more dangerous because it was believed that intelligence was hereditary and linked to race.

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False conclusions -

Racially biased scientists used the results of the military IQ tests to conclude that certain races were superior to others in terms of intelligence.

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Environmental influences -

They failed to understand the importance of environmental factors such as quality of education and healthcare. They created a racial hierarchy that naturally left minorities and newly arrived immigrants at the bottom.

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Implications -

These erroneous findings were used to influence government policies. The State of Virginia approved forced sterilization of people with low IQ scores. This practice was continued until 1974.

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Nazi Germany -

In Germany, the Nazi government approved the murder of children with low IQ scores.

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Uses in psychology -

In the mid-20th century, the IQ test was used by psychologists in an attempt to diagnose severe mental illnesses.

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Diagnosis -

The test was used to diagnose conditions such as depression and schizophrenia, which could land a person in a psychiatric hospital.

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Outdated methods -

Psychiatric patients were subjected to a range of barbaric treatments in this era.

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Progress -

Thankfully, it was later discovered that the IQ test did not provide any clinically useful information and it was no longer used in diagnosis.

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New observations -

Scientists noticed that the IQ of the population rose with each generation.

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New observations -

It was happening too quickly to be genetic, so they began to understand that environmental factors have a significant impact on intelligence.

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Modern IQ testing -

The modern IQ test has evolved significantly, but it still only tests a person's reasoning and problem-solving skills.

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Modern IQ testing -

Unfortunately, some psychologists still use it to diagnose learning disabilities, which can decide a child's educational experience and seriously impact their future.

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Modern IQ testing -

We still don't have a way to test for general intelligence and there is certainly no test that can measure a person's potential.

If modern researchers agree on one thing, it would be that individuals cannot be categorized by a single numerical score.

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See also - Find out more about another dark moment in the history of psychology! Follow this link to learn about the controversial Stanford Prison Experiment.

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