Most psychologists today think of intelligence as a group of related abilities, including reasoning ability,
and the speed with which the brain processes information.
Majority of the intelligence tests in use reflect this view of intelligence as something multifaceted.
Some tests measure just three components of intelligence: verbal, numerical, and reasoning abilities.
Others measure such factors as memory span, verbal fluency, spatial perception, and the ability to classify, generalize, and reason by analogy.
After the age of seven or so, a person’s IQ tends to stay about the same for the rest of his life. There are exceptions. Some studies show significant changes attributable at least partly to motivation and emotional factors.
Scientifically sound studies of directed efforts to raise IQ are limited, and the question of whether or not such efforts can succeed is much debated because of the nature or nurture aspect of intelligence.
One scientist who did not believe that IQ is fixed was the leading American evolutionary biologist Stephen Jay Gould. ‘We know,’ he said, `that “heritable” does not mean “inevitable.” Genes do not make specific bits and pieces of a body; they code for a range of forms under an array of environmental conditions. Moreover, even when a trait has been built and set, environmental intervention may still modify inherited defects.’
So in short, while there is strong evidence that intelligence is ‘inheritable’ there is also supporting evidence that environment can and does affect our intelligence.
Striking the `right’ balance is the key to a higher IQ.