Few issues have sparked such heated debate within the scientific community and society at large as that of intelligence and intelligence testing. Much of the controversy that has been raging for centuries centres on the very definition of the word “intelligence” as well as the ever present nature-nurture problem; that is, how much is an individual’s intelligence determined by heredity and how much is determined by environmental factors? Throughout the history of the debate, there have been no clear conclusions drawn, no definitive answers reached; yet there are many hypotheses, all of which have an overwhelming body of evidence to support them. This essay will begin by looking at meaning of the word “intelligence” and how it is currently measured. Here, as in later sections, much of the discussion is devoted to the dominant psychometric approach, which has inspired the most research up to this time and is the most widely used in practical settings. Nevertheless, several theories on the multiplicity of intelligence deserve serious consideration and will also be examined. Both sides of the heredity-environment argument over intelligence will then be looked at and critically discussed. The aim of the essay is to highlight the absurdity of extremist points of view from either side of the nature-nurture debate since a trait such as intelligence is a result of the complex interplay between both genes and environment.
What is Intelligence?
Part of the problem regarding intelligence stems from the fact that nobody has adequately defined what intelligence really means due to the abstract nature of the concept. Definitions of intelligence have been evolving for centuries and have always been largely dependent upon current social values as much as any scientific evidence (Geary, 2005). It is clear that individuals differ from one another in their ability to learn, to reason and to understand ideas. But although these differences can be...