[ExI] LA Times: Does your brain have a mind of its own?
pjmanney at gmail.com
Thu May 8 23:51:41 UTC 2008
Gary Marcus of NYU writes an op-ed piece from his book "Kluge: The
Haphazard Construction of the Human Mind".
It is this juryriggedness of our brains that makes me wonder just how
close we will come to accurately replicating human thought in another
>From the Los Angeles Times
Does your brain have a mind of its own?
Why can't we stick to our goals? Blame the sloppy engineering of evolution.
By Gary Marcus
May 4, 2008
How many times has this happened to you? You leave work, decide that
you need to get groceries on the way home, take a cellphone call and
forget all about your plan. Next thing you know, you've driven home
and forgotten all about the groceries.
Or this. You decide, perhaps circa Jan. 1, that it's time to lose
weight; you need to eat less, eat better and exercise more. But by the
first of May, your New Year's resolutions are a distant memory.
Human beings are, to put it gently, in a unique position in the animal
world. We're the only species smart enough to plan systematically for
the future -- yet we remain dumb enough to ditch even our most
carefully made plans in favor of short-term gratification. ("Did I say
I was on a diet? Mmm, but three-layer chocolate mousse is my favorite.
Maybe I'll start my diet tomorrow.")
In a wonderful study conducted at Stanford University in the late
1960s, psychologist Walter Mischel offered preschoolers a choice: a
marshmallow now, or two marshmallows if they could wait until he
returned. And then, cruelly, he left them alone with nothing more than
themselves, the single marshmallow, a hidden camera and no indication
of when he would return.
A few of the kids ate the oh-so-tempting marshmallow the minute he
left the room. But most kids wanted the bigger bonus and endeavored to
wait. So they tried. Hard. But with nothing else to do in the room,
the torture was visible. The kids did just about anything they could
to distract themselves from the tempting marshmallow that stood before
them. They talked to themselves, bounced up and down, covered their
eyes, sat on their hands -- strategies that more than a few adults
might on occasion profitably adopt. Even so, for about half the kids,
the 15 to 20 minutes until Mischel returned was just too long to wait.
Toddlers, of course, aren't the only humans who melt in the face of
temptation. Teenagers often drive at speeds that would be unsafe even
on an autobahn, and people of all ages have been known to engage in
unprotected sex with strangers, even when they are perfectly aware of
the risks. (To say nothing of the daily uncontrollable choices of
alcoholics, drug addicts and compulsive gamblers.)
What gives? Why are we as a species so often so desperately poor at
achieving our goals? If we are, as the selfish-gene theory would have
it, organisms that exist only to serve the interests of our genes, why
do we waste so much of our time doing things that are not, in any
obvious way, remotely in the interest of our genes? How can one
explain, for example, why a busy undergraduate would spend four weeks
playing "Halo 3" rather than studying for his exams?
The selfish-gene theory doesn't, in itself, answer these questions,
but there is another facet of evolution that can: The fact that
evolution is entirely blind, unable to look forward, backward or to
the side. As Charles Darwin observed, evolution invariably proceeds
through a process called "descent with modification." In lay language,
this means that Mother Nature never starts from scratch, no matter how
useful an overhaul might be. Everything that evolves necessarily
builds on that which came before. Our arms, to take one simple
example, are adaptations of the front legs of our primate ancestors.
In practical terms, that means that evolution's products aren't always
particularly sound. Truly dismal solutions are quickly weeded out; if
someone has a genetic condition that brings them into the world
without a functioning heart, they don't live long enough to reproduce.
But merely adequate solutions (what engineers call "kluges") -- like
the awkward, injury-prone human spine, good enough but far from
perfect -- can stick around indefinitely if better solutions are too
far away on the evolutionary landscape.
In the mental machinery that governs our everyday decisions, kluges
abound. Take, for example, the scenario described in the beginning of
the essay -- the fellow who forgets his errand on the way home. His
problem is clearly not in finding his way to the grocery store -- it's
in remembering to go in the first place.
The problem is that evolution failed to realize that remembering goals
is not like recognizing objects. When your brain sees a lion, the
thing to do is to decide, lickety-split, to get out of the way. Run
first; ask questions later. We're programmed for just that kind of
split-second decision; just about every creature on the planet is
built such that it can identify things like predators and prey very
rapidly. We're not programmed to remember precise episodes from the
past. Why not? Because remembering the exact date on which you last
saw a lion is not particularly helpful when you're trying to get out
of the way.
Alas, evolution didn't have the foresight to realize that different
kinds of tasks require different kinds of memory, and it used the same
basic sort of memory for everything, not just for remembering what
lions and tigers look like (in which general tendencies suffice) but
also for cases -- like tracking our goals -- where a bit more
precision would have been helpful. As a result, trying to remember
what to do next can be a little like trying to remember what you had
for breakfast yesterday: There are too many breakfasts and too many
yesterdays for our biological memories to keep track of.
The same thing can happen with our goals. When you sit in your car
late in the day and ask yourself, "What am I supposed to do next?" and
all of a sudden the cellphone rings, your brain can easily lose track
of which "next step" is the right one. Instead of zeroing in on the
specific memory it needs, it may well settle for remembering whatever
you've done in the car most often -- and that's drive home. Voila,
Our attempts to pursue our goals are often thwarted by the fact that
evolution has built our most sophisticated technologies on top of
older technologies -- without working out how to integrate the two. We
can plan in advance, using our modern deliberative reasoning systems,
but our ancestral reflexive mechanisms, which evolved first, still
basically control the steering wheel. When the chips are down, it's
those mechanisms that our brains turn to, and that means that our
brains frequently wind up relying on machinery that is all about
acting first and asking questions later, squandering some of the
efforts of our deliberative system.
No sensible engineer would have designed things this way. Why design
fancy machinery for making long-term goals if you're not going to use
it? Yet the brain is structured such that the more tired, stressed or
distracted we are, the less likely we are to use our forebrains and
the more likely to lean back on the time-tested but shortsighted
machinery we've inherited from our ancestors.
Still, all is not lost. Even though our short-term desires are pretty
good at grabbing the steering wheel of our consciousness, our more
recently evolved deliberate minds are powerful enough to regain at
least some measure of control.
Consider, for example, the difficulty that most people having in
sticking to abstract goals like "I intend to lose weight" or "I plan
to finish this article before the deadline." Nice thoughts, but not
formulated in terms that your ancestral, reflexive brain might
understand. The work-around? Translate those abstract goals into a
form your ancestral systems -- which traffic largely in dumb reflexes
-- can understand: if-then. If you find yourself in a particular
situation, then take a specific action: "If I see French fries, then I
will avoid them." As Peter Gollwitzer, my colleague in New York
University's department of psychology, has shown, even simple changes
like these can markedly increase the chances of success.
Our conscious, deliberate systems will never have total control, and
our memories will never be perfect, but as they say in Alcoholics
Anonymous, recognition is the first step. If we come to recognize our
limitations, and how they evolved, we just might be able to outwit our
Gary Marcus, a professor of psychology at New York University, is the
author, most recently, of "Kluge: The Haphazard Construction of the
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