James Harrison, of Westland High School, asks :-

Why is it that some people are more intelligent than others?

Bruce Jamieson, a psychologist at the University of Canterbury, responded.

Intelligence involves a person's capacities to learn from experience and to adapt to his or her environment.

We can see these capacities in action everyday, in the ways people go about solving problems and in their verbal, numerical and reasoning abilities, as well as their ability to deal with information. There are many varieties of intelligence tests but in general they contain items or problems which try to measure some of the abilities mentioned before.

For many years, psychologists considered that a person's level of intelligence was relatively fixed and that it was the result of the genes he or she had inherited from his or her parents. For example, identical twins who had been separated by adoptions soon after birth and been raised in very different families, were found much later to have similar levels of intelligence. The similarities were almost as great as those for identical twins who had been raised together.

Other research shows quite clearly that intelligence is also influenced by a person's experiences, particularly those in the early years of childhood. That is one reason why parents are often encouraged to read stories frequently to young infants, even before the children have begun to speak.

In general psychologists accept that both genes and experience are influential, and believe that it is more important to know the extent to which either very helpful and rich environments and experiences, or ones which are not stimulating, can influence intelligence levels upwards, or downwards, from the potentials we each inherit.