Spearman vs. Gardner: Two Theories of Intelligence

Introduction

Psychologists define intelligence as a "general capacity to acquire knowledge" (Huffman 2003: 319). This knowledge allows a person to learn from experience and observation. Intelligence also allows humans to adapt to changes in their environment, or to adapt the environment itself through manipulation and the use of tools.

There is much debate, however, regarding the nature of intelligence and what cognitive functions comprise it. This paper compares and contrasts two prevailing theories of intelligence: one proposed by Charles Spearman and one proposed by Howard Gardner.

Spearman's Model of General Intelligence

In the early part of the twentieth century, most psychologists considered intelligence an innate capacity that brought together all the different cognitive functions. Charles Spearman was a proponent of viewing intelligence as one single factor, which he called "general intelligence," or g. Spearman proposed that g underlies all forms of intellectual ability, from problem solving to reasoning to performing well on tests designed to measure intelligence.

As evidence of this single-ability concept, Spearman observed that separate tests of mental abilities tended to be positively correlated. A person who performs well on tests of spatial reasoning, for example, also tends to perform well on tests that measure general reasoning ability. For Spearman, this correlation pointed to an underlying intelligence — g — that governed all aspects of a person's cognitive skills (Huffman 2003).

Spearman's model had a significant influence on subsequent psychologists and continues to underpin standardized testing today. The standard exit exams administered in high schools, for example, are designed to measure whether a student is performing at grade level relative to peers. The standard IQ tests based on the work of Alfred Binet and Lewis Terman are likewise grounded in the idea of a single-ability measure of intelligence.

Cattell's Refinement: Fluid and Crystallized Intelligence

Spearman's model significantly influenced psychologists such as Raymond Cattell. Cattell's contribution, however, represented a more nuanced analysis of g. He proposed that a single form of intelligence did exist, but that it took two distinct forms.

The first is fluid intelligence, designated gf, which measures an individual's ability to reason, memorize, and process information quickly. For Cattell, gf was inherent and generally did not change with level of education, though it was observed to decline with age. The second form, crystallized intelligence or gc, measures the knowledge and skills acquired through experience and education. This form of intelligence increases across the lifespan, as long as people continue developing their cognitive abilities (Huffman 2003).

Gardner's Theory of Multiple Intelligences

Together, Spearman's and Cattell's work on g forms the conceptual basis of much standardized testing in use today.

The idea of a single g factor has numerous critics. As early as 1938, psychologist L. L. Thurstone criticized the narrowness of Spearman's model, arguing that mental abilities such as verbal comprehension, spatial visualization, and reasoning were distinct forms of intelligence that should be considered separately from one another (Huffman 2003).

Howard Gardner, a cognitive theorist, pursued this idea further by proposing a theory of multiple intelligences. Gardner devised a framework of eight intelligences, including linguistic skills, bodily-kinesthetic skills, and logical-mathematical skills. According to Gardner, people can have different profiles of intelligence, meaning they may face challenges in some areas while exhibiting strengths in others. Because of these different forms of intelligence, Gardner also proposed that people have distinct learning styles (Huffman 2003). A person with strengths in kinesthetic and spatial intelligence, for example, will have very different learning preferences from someone with strong linguistic and logical-mathematical skills.

Conclusion: Toward a More Inclusive Theory

Gardner's idea of multiple intelligences is now emerging as the major theory of intelligence, and for good reason. Previous measures relied heavily on ethnocentric cultural values, such as the emphasis on reading and verbal logic. Nomadic cultures, for instance, would certainly place a primacy on spatial reasoning — a form of intelligence that is largely overlooked under measures of g.