The notion that the different "kinds" of
intelligence, such as
logic, linguistic ability and spatial awareness,
correlate closely enough that people can be said to have a general level of intelligence, often abbreviated simply to
g.
The term was introduced by the statistician Charles Spearman in the early 20th century, when he noticed the correlation between people's scores on different kinds of IQ tests. The correlation is generally perceived to be too strong to be a statistical fluke, and is evidence that intelligence has a significant genetic component.