Free Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School by John Medina

deal of the structure and function of the brain is predictable, a property that allows the word “science” to be attached to the end of the word “neuro” and keeps people like me employed. Such similarity may be the ultimate fruit of the double-humped developmental program we talked of previously. That’s the experience-independent wiring.
    It’s when you get to the smaller routes—the brain’s equivalent of residential streets, one-laners and dirt roads—that individual patterns begin to show up. Every brain has a lot of these smaller paths, and in no two people are they identical. The individuality is seen at the level of the very small, but because we have so much of it, the very small amounts to a big deal.
    It is one thing to demonstrate that every brain is wired differently from every other brain. It is another to say that this affects intelligence. Two scientists, a behavioral theorist and a neurosurgeon, offer differing perspectives on the subject. The theorist believes in seven to nine categories of multiple intelligence. The neurosurgeon also believes in multiple categories. He thinks there may be billions.
    Meet Howard Gardner, psychologist, author, educator, and father of the so-called Multiple Intelligences movement. Gardner had the audacity to suggest that the competency of the human mind is too multifaceted to be boiled down to simplistic numerical measures. He threw out the idea of IQ tests, and then he attempted to reframe the question of human intellectual skill. Like a cognitive Jane Goodall in an urban jungle, Gardner and his colleagues observed real people in the act of learning—at school, at work, at play, at life . He began to notice categories of intellectual talent that people used every day that were not always identified as being “intelligent” and certainly were not measurable by IQ tests. After thinking about things for a long time, he published his findings in a book called Frames of Mind: The Theory of Multiple Intelligences . It set off a firestorm of debate that burns unabated to this day.
    Gardner believes he has observed at least seven categories of intelligence: verbal/linguistic, musical/ rhythmic, logical/mathemati-cal, spatial, bodily/ kinesthetic, interpersonal, and intrapersonal. He calls these “entry points” into the inner workings of the human mind. The categories don’t always intersect with one another, and Gardner has said, “If I know you’re very good in music, I can predict with just about zero accuracy whether you’re going to be good or bad in other things.”
    Some researchers think Gardner is resting on his opinion, not on his data. But none of his critics attack the underlying thesis that the human intellect is multifaceted. To date, Gardner’s efforts represent the first serious attempt to provide an alternative to numerical descriptions of human cognition.
    mapping the brain
    But categories of intelligence may number more than 7 billion—roughly the population of the world. You can get a sense of this by watching skilled neurosurgeon George Ojemann examine the exposed brain of a 4-year-old girl. Ojemann has a shock of white hair, piercing eyes, and the quiet authority of someone who for decades has watched people live and die in the operating room. He is one of the great neurosurgeons of our time, and he is an expert at a technique called electrical stimulation mapping.
    He is hovering over a girl with severe epilepsy. She is fully conscious, her brain exposed to the air. He is there to remove some of her misbehaving brain cells. Before Ojemann takes out anything, however, he has to make a map. He wields a slender white wand attached to a wire, a cortical stimulator, which sends out small, unobtrusive electrical shocks to anything it touches. If it brushed against your hand, you would feel only a slight tingly sensation.
    Ojemann gently touches one end of the wand to an area of the little girl’s brain and then asks her, “Did you feel