Intelligence, it is what set us apart from our primate ancestors. Human evolution led to the emergence of anatomically modern humans, beginning with the evolutionary history of primates—in particular genus Homo—and leading to the emergence of Homo sapiens as a distinct species of the hominid family, the great apes. Now since intelligence is a major factor in the distinction of humans from all other animals, we must understand what intelligence is. Intelligence has been defined in many ways: the capacity for logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. And in order to measure a person’s intelligence we need a method to scientifically determine the amount of intelligence factor a person has which is usually measured in terms of IQ.
In 1905, psychologists Alfred Binet and Théodore Simon designed a test for children who were struggling in school in France. Designed to determine which children required individualized attention, their method formed the basis of the modern IQ test. Beginning in the late 19th century, researchers hypothesized that cognitive abilities like verbal reasoning, working memory and visual-spatial skills reflected an underlying general intelligence or g factor. So, Simone and Binet designed a battery of tests to measure each of these abilities, and combine the results for a single score. Questions were made for each age group and a child’s score reflected how they performed relative to others in the same age group. Today a score of 100 is the average of a sample population, with 68% scoring within a 15-point radius. However, both then and now there is no single agreed upon definition of general intelligence. Which left the door open for people to use the test in service of their own preconceived assumptions about intelligence. What started as a way to identify those who needed academic help, soon became a tool to sort people in other ways, often in service of deeply flawed ideologies. One of the first large scale implementations occurred in the US during WWI when the military used IQ tests to sort recruits and screen them for officer training. However, that time people believed in Eugenics, the idea that desirable and undesirable genetic traits could and should be controlled in humans through selective breeding. This was a deeply flawed idea as it linked intelligence as not only fixed and inherited but linked to a certain race. This belief and results from IQ tests gave forth a wrong theory that certain races were superior than others, thus creating an erroneous intelligence hierarchy of ethnic groups. This not only influenced science but also policies in many countries. In 1924 Virginia ordered forced sterilization of anyone with low IQ scores, a decision that the supreme court of US upheld. We all know what happened in Nazi Germany due to such prevalent ideals, authorization of murder of children based on low IQ scores. Following the Holocaust and the Civil rights movement, the discriminatory usage of IQ tests was questioned on moral and scientific grounds. Scientists began gathering evidence as to how our environment impacts our IQ.
Today, IQ tests employ many similar design elements and types of questions as the early tests, though there are better techniques to identify potential bias in the tests. And due to many failed applications in the past they are no longer used to diagnose psychiatric conditions. And psychologists still use IQ tests to identify intellectual disability which can be used to determine educational support, job training and assisted living. As Alan Alda said “Be as smart as you can, but remember that it is always better to be wise than to be smart”.