The ability to measure intelligence sounds incredibly useful if you’re an educator or a scientist. But when you start to rule out the worst ideas (measuring skull circumference, for example) you realize that it’s a complicated task. Modern IQ tests claim to have a handle on these complications, but it’s still controversial whether they do this successfully.
History of the IQ Test
A French psychologist developed the predecessor to the IQ test in the early 1900s. The French government at the time asked Alfred Binet to create a system that would identify students who needed extra help in school. His test, created with his colleague Theodore Simon, attempted to measure aspects of intelligence that weren’t already being tested for in schools. He focused on attention, memory, and problem-solving in particular.
Binet found that sometimes younger children did even better than older children. He translated this into the idea of “mental age”. That concept influenced the development of the test, and later ones. Eventually the idea of the IQ score was based on a ratio of real age to mental age.
The Modern Test
Over the years, other psychologists and scientists have further tweaked and edited the Binet-Simon Scale. Many modern variations exist for different uses and different settings. One popular modern version is known as the WAIS-IV. The WAIS-IV (along with most modern tests) no longer relies on “mental age”, and instead compares test scores of similarly aged people together and centers the average at a score of 100. The WAIS-IV claims to measure four major areas of intelligence: verbal comprehension, perceptual reasoning, working memory, and processing speed.
The kinds of problems used to assess each category can be read on the Wechsler website.
As a result of its relatively long history and interest to sociologists, psychologists, and other scientists, the IQ test has featured prominently in many scientific studies. Some of these show distinct weaknesses in the test.
While links between IQ scores and academic and economic success have been found, that doesn’t necessarily indicate that the test measures intelligence specifically. One study, for example, indicated that a simple, but significant confounding factor exists: motivation. It turns out that the level of motivation of test-takers significantly influences the scores they receive. More motivated individuals succeeding in academic and economic measures seems logical – but if that’s the case, the link between success and high IQ is not entirely due to intelligence specifically.
In general, academic testing seems to be affected by all kinds of factors – sleep, nutrition, environment. Listening to Mozart might affect results. Reminding someone of their race or gender prior to a test can affect results. A particular test-taker’s score might vary some from year to year, or even day to day, depending on how well they feel overall and how much practice they’ve had.
Odd patterns that develop in the data are cause for question as well. The Flynn Effect, for example, shows a pattern of increasing IQ scores generation by generation. If you take IQ as a serious measure of intelligence, that would seem to indicate that human beings are steadily becoming more intelligent. This is certainly possible, but it’s hard to separate from other factors like increased familiarity with standardized testing.
So what do IQ tests measure?
IQ tests attempt to measure verbal comprehension, perceptual reasoning, working memory, and processing speed. We call the results of this the “intelligence quotient” or IQ for short. But is a high score in these four categories the best definition of intelligence? Do the confounding factors limit the ability of the tests to work? There isn’t a consensus among experts.
What we can say confidently: Sporcle can test your verbal comprehension, perceptual reasoning, working memory, and processing speed without all the pressure of a single numerical result. That’s why we call them mentally stimulating diversions. And hey, maybe throw on a little Mozart and it’ll give you the edge on those tough showdowns.