A normal IQ test includes several tests that measure intelligence. Such as the ability to recognize patterns, remember things quickly, do math, and think critically. People often get the wrong idea about IQ tests, thinking that they test all the information you've learned over the years. Instead, they test your ability to learn. 

The first IQ test was made in the early 1900s. Since then, it has changed a lot. In the same way that they tested people's abilities rather than anything they had learned in the past, their goal has stayed the same, and neither has the way they do it. 

The IQ test has been changed many times, but the Wechsler Adult Intelligence Scale (WAIS) is the one that is most often used. This test, which was made in 1955, was different from earlier IQ tests that looked at different mental skills, like verbal, numerical, spatial, and reasoning intelligence. There has been a change to this test, the WAIS-IV since it was first made. 

There are 10 subtests and five extra tests in the WAIS-IV. A verbal comprehension scale, a perceptual thinking scale, a working memory scale, and a processing speed scale are the four different types of intelligence that the test measures. Then, a person is tested with a group of friends to get a more accurate score, with two-thirds of the scores being in the normal range, which is between 85 and 115.