What is intelligence?

IQ tests are interpreted as measures of general intelligence or g-which is construed as a heritable component of the commonality among measures of intellect that relates to the acquisition of knowledge. Intelligence changes over life-span-it declines with age and the IQ phenotype becomes more congruent with the genotype. Intelligence is influenced by cohort specific exposures and requires exposure to formal education for its development. It is not easily changed and intelligence influences educational performance and occupational status.