Intelligence is the general ability to know and solve problems with first grade sight words.
What it is.
Intelligence is also understood as a system of all cognitive abilities of a person (perception, memory, thinking, imagination) and the ability to solve problems without 
trial and error in the mind. However, there are many paradoxical definitions of intelligence created by psychologists. “Intelligence is what intelligence tests measure,” Alfred Bean avoided answering when asked to tell us what it is. An even more elegant definition belongs to McNimar: “Everyone knows what intelligence and corresponding angles mean is. It is something that others do not have!”
Heredity or ability?
For a very long time there have been two opinions about intelligence. According to the first, intelligence is a purely hereditary trait: either a person is born intelligent or he is not. According to the second view, intelligence is related to the speed of perception or response to external stimuli. As early as 1816, the German astronomer Bessel claimed that he could determine the level of intelligence of his employees by the speed of their reaction to a flash of light.
Tests
In 1885, J. Kettel developed a dozen more “psychological” tests and https://argoprep.com/worksheet-generator/word-search/, which he called “mental” tests. These tests determined the speed of reflexes, reaction time, time to perceive certain stimuli, the pain threshold when pressing on the skin, the number of letters memorized after listening to the letter series, etc. With the help of these tests, Kettel determined the parameters of reactions to stimuli of different strengths.
In tests developed later, an indicator of performance was the time spent by the test taker on solving proposed tasks. The main measuring instrument for psychologists was 
the chronometer: the faster the examinee coped with the task, the more points he would score.
Meanwhile, scientists who developed the first prototypes of modern intelligence tests considered this property more widely. In their view, a person of intelligence was one who “judges correctly, understands and reflects,” and who, thanks to his “good sense” and “initiative” can “adapt to the circumstances of life.
This view was echoed by Wexler, the scientist who created the first adult intelligence scale in 1939. He believed that “intelligence is the global ability to act intelligently, think rationally, and cope well with the circumstances of life,” that is, in short, to “successfully measure up to the world around us.” Today, most psychologists agree with this very definition of intelligence, which is seen as an individual’s ability to adapt to the environment.
Three forms of intellectual behavior
Verbal intelligence (vocabulary, erudition, reading comprehension)
Problem-solving ability
Practical intelligence (the ability to get things done)
