A typical dictionary definition of intelligence is “the capacity to acquire and apply knowledge.” Intelligence includes the ability to benefit from past experience, act purposefully, solve problems, and adapt to new situations. Intelligence can also be defined as “the ability that intelligence tests measure.” There is a long history of disagreement about what actually constitutes intelligence.
Charles Spearman proposed a general intelligence factor, g, which underlies all intelligent behavior. Many scientists still believe in a general intelligence factor that underlies the specific abilities that intelligence tests measure. Other scientists are skeptical, because people can score high on one specific ability but show weakness in others.
In the 1980s and 1990s, psychologist Howard Gardner proposed the idea of not one kind of intelligence but eight, which are relatively independent of one another. These eight types of intelligence are:
Gardner believes that each of these domains of intelligence has inherent value but that culture and context may cause some domains to be emphasized over others. Critics of the idea of multiple intelligences maintain that these abilities are talents rather than kinds of intelligence.
Also in the 1980s and 1990s, Robert Sternberg proposed a triarchic theory of intelligence that distinguishes among three aspects of intelligence:
Some researchers distinguish emotional intelligence as an ability that helps people to perceive, express, understand, and regulate emotions. Other researchers maintain that this ability is a collection of personality traits such as empathy and extroversion, rather than a kind of intelligence.