How Geniuses Work

Your brain regulates your body's organ systems. When you move around, it sends impulses along your nerves and tells your muscles what to do. Your brain controls your senses of smell, taste, touch, sight and hearing, and you experience and process emotions using your brain. On top of all that, your brain allows you to think, analyze information and solve problems. But how does it make you smart?

Scientists haven't figured out exactly how all the gray matter in your brain works, but they do have an idea of which part lets you think. The cerebral cortex, which is the outermost part of your brain, is where thought and reasoning happen. These are your brain's higher functions -- the lower functions, which relate to basic survival, take place deeper in the brain.

Your cerebral cortex is the largest part of your brain, and it's full of wrinkles and folds that allow it to fit in your skull. If you removed and stretched out an adult human's cerebral cortex, it would be about as large as a few pages of a newspaper. It's divided into several lobes, and different regions within these lobes handle specific tasks related to how you think. Here's a quick overview of what each lobe handles:

It's obvious that your cerebral cortex has a big impact on how you think. But studying exactly how it makes you smart is a little tricky, because:

In spite of all those challenges, researchers have figured out a few things about how the brain affects intelligence. A 2004 study at the University of California, Irvine found that the volume of gray matter in parts of the cerebral cortex had a greater impact on intelligence than the brain's total volume. The findings suggest that the physical attributes of many parts of the brain -- rather than a centralized "intelligence center" -- determine how smart a person is.

A 1999 analysis of Albert Einstein's brain also seems to support this theory. Einstein's brain was slightly smaller than the average brain. However, parts of his parietal lobe were wider than most people's brains. The larger areas in Einstein's brain are related to mathematics and spatial reasoning. Einstein's parietal lobe was also nearly missing a fissure found in most people's brains. Analysts theorized that the absence of the fissure meant that different regions of his brain could communicate better.

A 2006 paper in the journal "Nature" theorized that the way the brain develops is more important than the size of the brain itself. A person's cerebral cortex gets thicker during childhood and thinner during adolescence. According to the study, the brains of children with higher IQs thickened faster than those of other children. Studies also suggest that, to some extent, children inherit intelligence from their parents. Some researchers theorize that this is because the physical structure of the brain can be an inherited trait. In addition, the process of becoming really good at something both requires and encourages your brain to wire itself to handle that particular task better.

Even though scientists are not sure exactly how or why it happens, it's clear that the human brain plays a part in determining a person's intelligence. But what's the difference between genius and intelligence? And what makes one person more intelligent than another? We'll look at how intelligence relates to genius next.

Like genius, intelligence can be difficult to quantify. Psychologists and neuroscientists study intelligence extensively. An entire field of study, known as psychometrics, is devoted to studying and measuring intelligence. But even within that field, experts don't always agree on exactly what it is or how best to analyze it. And while intelligence is central to genius, not all geniuses score well on intelligence tests or perform well in school.

Intelligence testing has existed for thousands of years. Chinese emperors used aptitude testing to evaluate civil servants as early as 2200 BC [ref]. The tests we know as IQ tests got their start near the end of the 19th century. Today, IQ tests generally measure a person's memory as well as language, spatial and mathematical abilities. In theoretical terms, these tests measure a concept or factor known as g. You can think of g as a unit of measure or a way of expressing the amount of intelligence a person has.

IQ tests are also standardized so that most people score between 90 and 110. When placed on a graph, the IQ test scores of a large group of people will generally resemble a bell curve, with most people scoring in the average range. A common perception is that anyone scoring above a certain number -- often 140 -- is automatically a genius. But in spite of the existence of high-IQ organizations, many scientists caution that there is no such thing as a genius-level IQ.

Many educators and researchers feel that, in general, standardized IQ tests do a good job of predicting how well a child will perform in school. Schools often use these tests to determine which children to place in gifted or special education classes. Most colleges and universities and some employers also use standardized tests as part of their application processes.

However, in spite of their prevalence, these tests are not foolproof. In general, some minorities and people with lower income levels tend to score lower than people from other racial and economic groups. Critics contend that this makes IQ tests invalid or unfair. Others argue that they instead point out unfairness and prejudice within a society.

In addition, some researchers and theorists argue that the concept of g is too limiting and doesn't really give a full view of a person's intelligence. These researchers feel that intelligence is a combination of many factors. One theory that tries to provide a more complete view of intelligence is Howard Gardner's theory of multiple intelligences (MI). According to Gardner, there are seven types of intelligence:

Many parents and educators feel that these categories more accurately express the strengths of different children. But critics allege that Gardner's definitions are so broad and inclusive that they make intelligence meaningless.

Another less restrictive theory is Robert J. Sternberg's triarchic theory of human intelligence. According to Sternberg, human intelligence includes:

In Sternberg's view, a person's total intelligence is a combination of these three abilities. Critics claim that he has little empirical evidence for his theories. They also argue that practical intelligence is not intelligence at all, or that it can be explained through other theories of intelligence.

The triarchic and MI theories are both relatively new, and critics have pointed out flaws in both of them. However, they may be better able to explain the concept of genius than traditional IQ tests can. Geniuses aren't just people with a lot of g. Mozart, for example, combined musical genius with an innate understanding of mathematics and patterns. Einstein's genius spanned the realms of logic, math and spatial relationships. And all geniuses have a very important aptitude in common -- they have an abundance of creative intelligence. Without it, they wouldn't be geniuses. They'd simply be exceptionally smart.

How much creativity does it take to be a genius? We'll look at how imagination and productivity contribute to genius next.

There's a big difference between being really smart and being a genius. While geniuses tend to be exceptionally intelligent, they also use imagination and creativity to invent, discover or create something new within their field of interest. They break new ground rather than simply remembering or reciting existing information.

Geniuses do not usually operate in isolation, either -- nearly all of them analyze the work of other great minds and use that information to make new discoveries. Self-taught geniuses, on the other hand, often explore information in unexpected or inventive ways, due in part to their lack of formal training. In either case, the ability to imagine new possibilities is as important as general intelligence.

Like intelligence, creativity and imagination can be difficult to isolate, quantify or explain. Some researchers believe that creative people have less latent inhibition than other people. Latent inhibition is the unconscious ability to ignore unimportant stimuli. Researchers theorize that creative people either receive more stimuli from the world around them or ignore less of it. This may also explain why creative people seem to be more prone to mental illness. People who are both unable to filter stimuli and emotionally unstable are more prone to psychosis.

Creativity also seems to have some traits in common with bipolar disorder. During an episode of mania, a person with bipolar disorder experiences increases in energy, the ability to focus and motivation. Bipolar disorder is more common among writers and artists than in the general population, but scientists have not found a cause-and-effect relationship between the two.

The creativity of geniuses also relates to productivity and hard work. Sometimes, the most dramatic examples of genius involve people who produce their best work at a very young age. However, not every genius produces exceptional work early in life the way Einstein and Mozart did. Some, like Ludwig von Beethoven, do their best work later in life.

Researcher David Galenson theorizes that the reason for this is that creative people come in two main types:

Critics say Galenson's theories overlook people who produce exceptional work throughout their lives. His latest research suggests that creativity can be expressed as a continuum. Instead of being either experimental or conceptual, people can be mostly one or the other, or they can be somewhere in the middle.

We may never know precisely where creativity comes from, why some people use their creativity more than others or why some people are most creative during specific times in their lives. We may not learn how one person ends up with the right balance of brainpower, intelligence and creativity to become a genius. But it's clear that geniuses are central to advancements in science, technology and understanding. Without geniuses, our understanding of mathematics, literature and music would be completely different. Concepts that we now take for granted, like gravity, planetary orbits and black holes, might still be undiscovered.

Check out the links on the next page for lots more information about the human brain, intelligence and genius.