Intelligence Testing: Theories, Problems, and Current Practices

Introduction to Intelligence Testing Debates

The concept of intelligence has been controversial ever since it was first proposed as a quantifiable and measurable aspect of cognition and learning. Debates have not only revolved around the exact nature of intelligence — its neural and psychological mechanisms, origins, and influences — but the question of whether intelligence is even a valid or practical measure has also been raised. Due to this controversy, contemporary intelligence tests and studies that use intelligence measures directly or peripherally are generally designed to be as inclusive as possible, either drawing on previously established broad-based theories and tests of intelligence, or specifically and narrowly defining the aspect of intelligence being utilized in conjunction with a larger study. Both proponents and detractors rely on these established approaches in pursuit of greater truth, accuracy, and validity in intelligence testing, a tension that is clearly observable in current research.

Wechsler Scales and Accuracy at Low Intelligence Levels

Two of the most commonly used intelligence testing tools are the Wechsler Adult Intelligence Scale and the Wechsler Intelligence Scale for Children, both developed according to a broad definition of intelligence that emphasizes the ability to interact rationally and effectively with one's environment. In a recent study, these instruments were examined for possible predictive issues at low intelligence ranges; it was believed that the tests lost accuracy at lower levels due to their scaling mechanisms (Whitaker & Wood, 2007). Although this study found that such concerns were not statistically upheld, it illustrates the anxieties surrounding accuracy and validity in intelligence testing — particularly when results are used to make life-altering decisions for school children performing at the lower end of the scale.

Working Memory as an Alternative Predictor of Learning

This concern is one reason many researchers have attempted to find more objective and measurable indicators of academic success than traditional intelligence testing. The claim that intelligence is heavily influenced by culture and upbringing — and that intelligence tests reflect those same influences — is an attempt to challenge the fundamental premise of most intelligence theories. Instead, some researchers argue that more concrete, neurologically grounded mechanisms such as memory are more effective at determining levels of cognitive success (CJ, 2009). A careful comparison of working memory abilities — the capacity to retain and process auditory and visual information through rehearsal and manipulation loops — against standard intelligence testing at age five and again six years later showed that working memory was a substantially better predictor of learning outcomes, accounting for as much as twenty percent of the observed variation, far more than intelligence quotients (CJ, 2009).

Conclusion: Scientific Disagreement and Practical Pressure

Each of the above studies defines a different and somewhat incompatible method of conceptualizing and testing for intelligence, reflecting the continuing controversy that surrounds intelligence testing in general and several of its specific methodologies and applications. From a purely scientific point of view, this is not a problem; science advances through such disagreements and the theoretical shifts and refinements that follow from them. Given the practical and consequential uses to which intelligence tests are put, however, there is considerable real-world pressure to define intelligence as accurately as possible, and as quickly as possible. Despite their disagreement — indeed, because of it — these studies promise to further that goal.