Theories on intelligence
Theories of intelligence can roughly be divided into two schools of thinking. The first assumes that there is one general ability. The second assumes there are multiple intelligences, meaning there are different forms of intelligence which are independent.
The thought that there is only one intelligence arose from the observation that different components, all assumed to be related to intelligence, are correlated. Apparently they are not different things but they share something. This school of thought is often referred to as the theory of General Intelligence, and abbreviated to the G factor.
Others assume that there are multiple forms of intelligence which are independent. For example, a person can have great linguistic abilities, while having trouble performing the simplest calculations. A football player can have a high 'body-kinesthetic intelligence', but be completely devoid of any musical talents.
Commonly used intelligences
In science and in the practice of the IQ test, usually four intelligence types are distinguished. Tests of these four intelligence types together determine the IQ score. Typically an intelligent person will score higher on all components than someone who is less intelligent. People that are extremely good in one component and very bad in another, are very rare.
Verbal intelligence is the ability to understand, use and learn language. Quick understanding of text and a large vocabulary are indicators of a high verbal intelligence. If a person makes many linguistic errors, that can be a sign of a lower intelligence. It may also be the simple result of inaccuracy.
Calculations are traditionally the most commonly used method of measuring intelligence. Often a mix of pure calculation and logical calculation is used. In addition, an arithmetic problem can be expressed in words, so the verbal intelligence is involved too.
Whether or not someone is capable of solving complex spatial problems determines the spatial intelligence. 'Mentally rotating' objects or discovering order in shapes are commonly used question types. Your spatial intelligence can be improved by practicing spatial reasoning.
Being able to reason logically is sometimes seen as the overarching ability. Logical questions or asking a person to draw the right conclusions can be embedded in verbal, numerical and spatial questions.