Way back, when TV news magazine shows did something besides murder, one of them aired a piece on Nigerian con artists.

The report centers on a certain “highly regarded” East Coast doctor who fell for an almost laughably implausible con called the “Black Money Scam.” The audience is reminded at least a dozen times that the victim is a “heart surgeon,” a job that, like rocket scientist and quantum theorist, is synonymous in the public mind with superior intelligence.

Hour-long story short, the heart surgeon was induced to pay the Nigerians hundreds of thousands of dollars for a large suitcase containing what they assured him were millions in U.S. currency. The way the Nigerians explained it, each individual bill had been painted black, ostensibly to fool customs officials, making the contents appear to be nothing more than thick money-sized bundles of black construction paper, which, in fact, they were.

“If a heart surgeon can be fooled by these scammers,” the correspondent ominously intoned, “we are all at risk.”

Really? It’s a good bet the guy who lubes the surgeon’s BMW wouldn’t fall for it, or the gal who trims his thinning salt-and-pepper hair, or even the kid who mows his plush 2-acre lawn. In fact, at least 330 million Americans would know better than to bet the farm on a handshake with a stranger in a hotel room.

There’s no question that the unhappy heart surgeon is superbly trained. There’s no doubt that he’s highly skilled. By all accounts he’s an excellent heart surgeon. But intelligent? Gonna’ want a second opinion.

Even the really smart have a hard time saying what counts for smart. People can be sharp in many different ways, and stupid in just as many. We’ve all heard about physical intelligence, social intelligence, emotional intelligence—pick your adjective and somebody somewhere is smart like that. But if being able to play Chopin’s Etude Opus 25 No. 11 perfectly after hearing it one time is a remarkable mental feat, it’s too narrow a test of cognitive acuity. At bottom, intelligence is the ability to efficiently assess data, identify relationships within, and draw rational conclusions therefrom. If one’s intellectual gift can’t be applied equally to a broad range of endeavors, it’s really more of an aptitude, a knack. Think “Renaissance Man” as opposed to “Idiot Savant.”

There are as many different definitions of intelligence as there are experts in that field. The Oxford English Dictionary calls it “the ability to learn, understand and think in a logical way about things.” Webster’s says it’s “the ability to apply knowledge to manipulate one’s environment.” Cambridge considers it intelligent to “make judgments or have opinions that are based on reason.” Columbia pulls out all the stops, deeming intelligence “the general mental ability involved in calculating, reasoning, perceiving relationships and analogies, learning quickly, storing and retrieving information, using language fluently, classifying, generalizing, and adjusting to new situations.” Note that nobody’s definition suggests a link between intelligence and education.

If deep thinkers aren’t quite together on how exactly to define intelligence, most of them can agree on its essential ingredients. The first, and arguably most important, element of intelligence is short-term memory. You’ve got to have grist before you can grind, and raw information is the brick and mortar of your intellect. The bigger your stockpile of ready information—any information—the bigger your potential intellectual edifice.

The second crucial element of smarts is being able to use knowledge to create knowledge. It’s “abstract thinking,” identifying connections between disparate factoids and forging them into something new. Within that ability to infer is the bridge between learning and understanding, and it’s the foundation of discovery, of creativity, of judgment, of progress.

What’s the use of knowing how to turn dirty diapers into diamonds if you can’t tell anyone how it’s done? The third piece of the intelligence puzzle is the ability to communicate effectively. It’s not enough to think something smart, you need to be able to share it.

By now you’re probably wondering if there’s a way to make yourself more intelligent.

Um… maybe.

There’s considerable evidence that we’re each about as smart as we’re individually constructed to be. But there’s just as much evidence that most of us aren’t making the best use of the brains we were born with.

For instant results, try improving your diet and getting more sleep. Like every other part of the body, the brain works better when fed and rested.

Expand your areas of interest, and take the time to dig in a little. And don’t just pack in the facts, chew on them a while. Book clubs, music clubs, even celebrity fan clubs are great for examining ideas from diverse perspectives. Keeping a journal will not only help you weigh and crystallize new concepts in your own mind, it will improve your ability to discuss them intelligently with others.

The core processes of intelligence are pattern recognition and problem solving, both of which can be learned and practiced. Although it pains to say, go ahead and play those stupid little “brain games” on your smart phone. They’re silly and distracting and irritating to everyone around you, and they’re reasonably good mental exercise.

Before you undertake a mental makeover, however, be sure you need one. Experts contend that most people tend to underestimate their relative intelligence, usually because they feel intimidated by people who overestimate their own. The fact is, you’re probably smarter than you give yourself credit for, and in any case a little intellectual humility is a good thing. “The wise man knoweth himself to be a fool,” whereas people cocksure of their own genius are prone to making impulsive decisions based more on their own sense of mental infallibility than on cool reasoning.

Still, if you’re like most people, you can’t shake the feeling that you just don’t mentally measure up to anyone with a prestigious degree, or a distinguished job, or a big house on 2 green Long Island acres. That’s human nature. But if you’ve never blown your life savings on a suitcase full of trash, then you’re already smarter than at least one heart surgeon.