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Cognitive Abilities Theory

The next five chapters introduce you to some powerful emerging theories and ideas about human intelligence. We’ll imagine them as parts of an elephant — that is, we’ll focus on the ways in which they’re different from each other. Behind that appearance of disunity, you know we’re already exploring the parts of the Intelligence River — the unity that will eventually emerge. But by seeing their differences clearly, you’ll discover the separate contribution each one makes to the unified whole. So, grab your kayak, raft, or inner tube, and let’s take a ride down our first tributary!

Laying a Foundation

Cognitive Abilities Theory will build your foundation for a broadened understanding of intelligence. This way of thinking about intelligence looks for the basic building blocks — the separate but related abilities — from which intelligent behavior is constructed. This way of looking at intelligence can seem both jargon-laden and fragmented. For one example, how does "Ideational Fluency" help you raise a smarter kid?

Is your first reaction to this way of looking at intelligence negative? For many people, it’s a bit atomistic. How can looking at all these tiny blocks ever add up to anything important? It may help you to think about how medical students study the human body: To eventually understand how the whole body works as a unified system, it’s important to understand the molecular-level chemical reactions that underlie the big patterns. Basic matters matter!

We each have a mix of cognitive abilities — a profile with some stronger abilities and some weaker ones. Cognitive ability theorists hope that one day we’ll be able to define all the cognitive abilities and profile them for individuals — imagine drawing a graph showing each person’s pattern of strengths and weaknesses for every important aspect of intelligence.

Cognitive Abilities Theory is supported by evidence from children’s development, brain research, and genetic studies, but the core of the theory lies in the belief that a powerful statistical method called factor analysis will help us see the structure of intelligence. Factor analysis is fairly heavy stuff, but fortunately, you don’t need to understand much about how it works. It’s enough to say that it starts with a huge mountain of numbers and reduces them to something we can make sense of.

For example, imagine that you and I and several hundred other people spend the day in a psychologist’s laboratory (scary idea!) doing all kinds of tasks. Our researcher scores each person’s performance on each test. She ends up with a mountain of information about us. But what does it all mean?

A factor analysis can help answer that question. For example, it might show that one part of what was being measured in all the tests we took was how fast we responded. So now our researcher has a factor — she might call it response speed — which teases out one small part of what all the tests were really measuring. At the end of the process, a few factors summarize the relationships in her research data, and help make sense of the overwhelming mass of information she started with. It’s these factors we’ll be dealing with here.

This way of thinking about intelligence took a giant step forward with the publication of a book called Human Cognitive Abilities: A Survey of Factor-Analytic Studies, by John Carroll. It is a dauntingly impressive work of scholarship. Since powerful enough data crunchers first became available, there have been hundreds of factor analytic studies of human abilities. Carroll reanalyzed and reviewed every major study — nearly 500 large bodies of data.

If one factor analysis summarizes a mountain of data, what John Carroll did was to make sense of a whole mountain range! His theory wants to show us a big picture, an overview, of the building blocks of human intelligence. He said that the structure of intelligence has three different layers — like a three-tiered organizational chart for a business, with a CEO at the top, several middle managers, and the rest of the company at the bottom of the chart. At the bottom, he identifies nearly 70 highly specific abilities with very technical names like Spatial Scanning and Ideational Fluency. Luckily for us, he simplifies the picture: He reanalyzes these narrow abilities, and clusters them into several broad abilities with names that make more intuitive sense. These are the names we’re going to use. But he goes one step further, and clusters these second-level factors into a single general factor at the top, a kind of highly abstracted across-the-board intelligence — just plain “smartness.” This top level is called general intelligence. It will come up again in the next chapter.

As I said, we’re only going to use the middle level of this three-level hierarchy. The 70 narrow abilities at the bottom give us too much detail to guide our work for our children, and the top, “general” level doesn’t give us enough detail to focus our efforts. (Whether “general intelligence” even exists, and whether it is a useful idea, has been the subject of a long and still-continuing debate.) So we’ll concentrate on that middle level.