Brain Rules (Updated and Expanded)

The brain remains malleable
Research shows that the brain is wired to keep learning as we age. Some
regions of the adult brain stay as malleable as a baby’s brain, so we can
grow new connections, strengthen existing connections, and even create
new neurons, allowing all of us to be lifelong learners. We didn’t always
think that. Until five or six years ago, the prevailing notion was that we
were born with all of the brain cells we were ever going to get, and they
steadily eroded in a depressing journey through adulthood to old age. We do
lose synaptic connections with age. Some estimates of neural loss alone are
close to 30,000 neurons per day. But the adult brain also continues creating
neurons within the regions normally involved in learning. These new
neurons show the same plasticity as those of newborns.

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Throughout life, your brain retains the ability to change its structure and
function in response to your experiences.
Why? Evolutionary pressure, as usual. Problem solving was greatly
favored in the unstable environment of the Serengeti. But not just any kind
of problem solving. When we came down from the trees to the savannah,
we did not say to ourselves, “Good Lord, give me a book and a lecture and
a board of directors so that I can spend 10 years learning how to survive in
this place.” Our survival did not depend upon exposure to organized,
preplanned packets of information. Our survival depended upon chaotic,
reactive information-gathering experiences. That’s why one of our best
attributes is the ability to learn through a series of increasingly self-
corrected ideas. “The red snake with the white stripe bit me yesterday, and I
almost died,” is an observation we readily made. Then we went a step
further: “I hypothesize that if I encounter the same snake, the same thing
will happen!” It is a scientific learning style we have exploited literally for
millions of years. It is not possible to outgrow it in the whisper-short seven
to eight decades we spend on the planet.
So it’s possible for us to continue exploring our world as we age. Of
course, we don’t always find ourselves in environments that encourage such
curiosity as we grow older. I’ve been fortunate to have a career that allowed
me the freedom to pick my own projects. Before that, I was lucky to have
my mother.
Encouraging curiosity with a passion
I remember, when I was 3 years old, obtaining a sudden interest in
dinosaurs. I had no idea that my mother had been waiting for it. That very
day, the house began its transformation into all things Jurassic. And
Triassic. And Cretaceous. Pictures of dinosaurs would go up on the wall. I
would begin to find books about dinosaurs strewn on the floor and sofas.
Mom would even call dinner “dinosaur food,” and we would spend hours
laughing our heads off trying to make dinosaur sounds. And then, suddenly,
I would lose interest in dinosaurs, because some friend at school acquired
an interest in spaceships and rockets and galaxies. Extraordinarily, my
mother was waiting. Just as quickly as my whim changed, the house would
begin its transformation from big dinosaurs to Big Bang. The reptilian

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posters came down, and in their places, planets would begin to hang from
the walls. I would find little pictures of satellites in the bathroom. Mom
even got “space coins” from bags of potato chips, and I eventually gathered
all of them into a collector’s book.
This happened over and over again in my childhood. I got an interest in
Greek mythology, and she transformed the house into Mount Olympus. My
interests careened into geometry, and the house became Euclidean, then
cubist. Rocks, airplanes. By the time I was 8 or 9, I was creating my own
house transformations.
One day, around age 14, I declared to my mother that I was an atheist.
She was a devoutly religious person, and I thought this announcement
would crush her. Instead, she said something like “That’s nice, dear,” as if I
had just declared I no longer liked nachos. The next day, she sat me down
by the kitchen table, a wrapped package in her lap. She said calmly, “So I
hear you are now an atheist. Is that true?” I nodded yes, and she smiled. She
placed the package in my hands. “The man’s name is Friedrich Nietzsche,
and the book is called