ABSTRACT
The notion is quite popular that the concept of "intelligence" is very modern and was invented by psychologists less than 100 years ago. It is also often said to be purely Western, and geared to capitalist economics. Many different consequences can be deduced from the postulation of a factor of general intelligence, but that does not imply disagreement on its nature. Before going into detail about Intelligence quotient (IQ) measurement, it may be useful to say a few words about the concept of intelligence, if only because it is often used in different ways by different people, or even by the same person in different contexts, and this often causes confusion. IQ tests and thermometers are more reliable, less subjective, and more valid than personal judgments based on experience, and furthermore they are capable of infinite improvement; yet there is a continuous line from the most elementary subjective notions to the most complex measuring instrument.
