No one knows exactly what we mean by intelligence, but as Justice Potter Stewart of the US Supreme Court said in 1964, “Intelligence is like porn, difficult to define, but you know it when you see it.” When we observe members of our species we see some who learn quickly, can solve problems easily, and can articulate ideas clearly. Others struggle with abstract concepts, learn more slowly, and have difficulty expressing themselves. To describe this variation in human capability, we use the term, intelligence. Unlike concepts in physics where qualities tend to have a more precise mathematical definition, the term intelligence is somewhat enigmatic. Perhaps the most widely accepted definition is the one articulated by psychologist Linda Gottfredson:
Intelligence is a very general mental capability that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience. It is not merely book-learning, a narrow academic skill, or test-taking smarts. Rather, it reflects a broader and deeper capability for comprehending our surroundings, “catching on,” “making sense” of things, or “figuring out” what to do.
When a person who doesn’t know much about a topic is speaking to others who are equally uninformed, they may appear to be knowledgable. However, when they are speaking to those who are knowledgeable about that topic, their limitations will be immediately obvious to those observers. The best way to be recognized as intelligent is to be open about what you know and don’t know. When top rate mathematicians or scientists write a paper, they usually begin by stating what is known and what is not known and proceed by sharing their failures (unproved conjectures) and their successes (what they’ve been able to prove through deduction or experiment.) Even outside the STEM subjects, where opinion plays a stronger role, the greatest scholars are usually frank about the limitations of their knowledge. The only people who speak with