Brain: How much does brainpower matter to success? Some surprising answers, only one of which matters much

In "High-Aptitude Minds: The Neurological Roots of Genius" (Scientific American Mind - September 3, 2008) Christian Hoppe and Jelena Stojanovic tell us that "Researchers are finding clues to the basis of brilliance in the brain."

The clues are pretty murky, and the whole area sounds confusing and contradictory in the article (which is not the writers' or the researchers' fault - it is more likely due to the plasticity of the brain). For example,

No one is sure why some experiments indicate that a bright brain is a hardworking one, whereas others suggest it is one that can afford to relax. Some, such as Haier—who has found higher brain metabolic rates in more astute individuals in some of his studies but not in others—speculate one reason could relate to the difficulty of the tasks. When a problem is very complex, even a gifted person’s brain has to work to solve it. The brain’s relatively high metabolic rate in this instance might reflect greater engagement with the task. If that task was out of reach for someone of average intellect, that person’s brain might be relatively inactive because of an inability to tackle the problem. And yet a bright individual’s brain might nonetheless solve a less difficult problem efficiently and with little effort as compared with someone who has a lower IQ.

The most useful take-home information is this:

University of Pennsylvania psychologists Angela Duckworth and Martin Seligman examined final grades of 164 eighth-grade students, along with their admission to (or rejection from) a prestigious high school. By such measures, the researchers determined that scholarly success was more than twice as dependent on assessments of self-discipline as on IQ. What is more, they reported in 2005, students with more self-discipline—a willingness to sacrifice short-term pleasure for long-term gain—were more likely than those lacking this skill to improve their grades during the school year. A high IQ, on the other hand, did not predict a climb in grades.

In other words, one reason that a difference between highly intelligent people and the rest of us may be difficult to identify is that the difference is not necessarily reflected in real life performance.