Definitions of Intelligence

The ability to learn from experience, solve problems, and use knowledge to adapt to new experiences

A mental quality that consists of the abilities to learn from experience, adapt to new situations, understand and handle abstract concepts, and use knowledge to manipulate one’s environment

The ability to acquire and apply knowledge and skills

The ability to learn or understand things or to deal with new or difficult situations

The capacity for learning, reasoning, understanding, and similar forms of mental activity

First of all, it's very hard to measure out intelligence because it involves a lot of different factors such as ones culture, emotions, age, skill sets, thoughts and etc. Because of these factors and the way they influence our intelligence it's hard to define it and that's why we have so many definitions of intelligence. Most of them can be easily manipulated, therefore making them controversial. The four definitions that I have chosen are to some extent different, but similar and can be interpreted differently. The first, second and fourth definitions, all have emotions involved in them since they include experiences, new situations or environments. It's easier to adapt these two definitions to social situations than for example the third definition, since it doesn't involve emotions, similarly to the last definition. Even those the last and third definitions, both seem to have only knowledge and skills involved,  all five of these definitions have something in common, which is the ability to learn new things. 

In the video above, two theories and definitions of intelligence (Spearman's and Gardner's) are discussed and compared. This video also looks into the controversy of definitions of intelligence and ranking intelligence as well as dividing intelligence into different types of intelligence.