Dumb tricks your mind plays
Blame it on evolution — we’re not perfect! Some quotes from the article:
“Our brains have evolved to live in the moment…”
“Most pleasure springs from the ancestral, reflexive system…”
“Thinking of the brain’s pleasure system as a kluge…”
A new book argues that evolution is far from perfect: What makes the human brain wonderful also makes it an error-prone mess
The word kluge rhymes with stooge and is used by computer programmers to describe a clumsy solution to a problem. Computer pioneer Jackson Granholm, who popularized it in 1962, described a kluge as “an ill-assorted collection of poorly matching parts, forming a distressing whole.”
Sound like an apt description of your brain? New York University psychologist Gary Marcus thinks so.
In his new book, Kluge: The Haphazard Construction of the Human Mind, he argues that evolution has piled new systems on top of old ones inside our skulls. The result is two distinct ways of thinking – an ancestral system that is instinctual and reflexive and a more modern, deliberative one that involves reasoning.
The mix of the two helps to explain why the human brain is so prone to error, Dr. Marcus says. It is why our memories so often fail us, why we can’t resist French fries if they are put in front of us and why we watch so much television.
“Humans can be brilliant, but they can be stupid too. They can join cults, get addicted to life-ruining drugs and fall for the claptrap of late-night talk radio,” Dr. Marcus says.
Kluge, published by Houghton Mifflin and distributed by Thomas Allen & Son Limited in Canada, was released this week and is already generating a lot of buzz.
Dr. Marcus offers a less awestruck view of evolution than other authors who have tackled the topic. He’s a curmudgeon, ignoring the wonder and the beauty of how humans evolved from a single-celled organism. Instead, he focuses on what has gone wrong.
“In general, in science writing, there is this assumption that you must bow to nature – and there is plenty to bow to,” he says in a recent interview. “Don’t get me wrong – just because I pick on the rough edges doesn’t mean there aren’t pretty ones too. But those have been covered much better.”
He says the book is based on the concept of descent with modification, first put forward by Charles Darwin. In essence, it means that in the process of evolution, anything new is built on the substrate of something that was there before – the first wing was a modified forelimb, for example.
This is why the human spine is a kluge, Dr. Marcus says. It evolved from that of four-legged creatures, and is a lousy solution to the problem of supporting an upright, two-legged walker. He is not the first scientist to blame evolution for back pain, or to observe that the human brain is a mix of the old and the new. But in his book he marshals a broad array of evidence to describe the impact that our design flaws have on the way we think and behave.
The idea that the brain is a kluge became clear to Dr. Marcus when he was researching his last book, The Birth of the Mind, about how the brain gets built the same way the body does – by a small number of genes. It is not much of a leap, he says, to see that the brain, like other parts of our anatomy, is adequate, but far from perfect.
Consider, for example, the limitations of human memory. You can know a word, he says, but may not be able to remember it when you need it.
In comparison, computer memory is much more robust than the brain because programmers organize information into a giant map and each item is assigned a specific place in the databank. Dr. Marcus describes this as “postal-code memory” – when a computer is prompted to retrieve a particular memory, it simply goes to the right address.
In lieu of postal-code memory, humans developed “contextual memory,” he says. We pull things out of our memory by using context or clues that hint at what we are looking for. The system is built for speed, more than reliability, and is better at the quick retrieval of general information rather than specific details.
This allowed our ancestors to help find food and avoid dangers, but doesn’t make us very competent eyewitnesses in today’s court cases. It is why it is so much easier to remember where we usually put our keys, rather than where we put them last. It can make it hard to summon the name of a new neighbour you met last week.
Our brains have also evolved to live in the moment, Dr. Marcus says. Our ancestors were never sure about their next meal, so they ate whatever they could get. It is hard to overcome that ancestral tendency, he says. We are driven to load up on carbs and fat because we might not find any next week.
Most pleasure springs from the ancestral, reflexive system, Dr. Marcus says. It is the modern, deliberative system that can reason that eating too much fat and sugar is unhealthy. Guess which one prevails when a green-tea crème brûlée is set down in front of you?
“Yes, I may get a slight sense of satisfaction if I waive my opportunity to eat that crème brûlée, but that satisfaction would almost certainly pale in comparison to the kick, however brief, that I would get from eating it,” says Dr. Marcus, 38.
Thinking of the brain’s pleasure systems as a kluge helps to explain why humans goof around so much. Why, for example, we watch so much television, two to four hours a day on average. It is hard for the brain to overlook the short-term appeal of television in favour of other potentially more productive choices – like exercising or cleaning the house.
His book looks at many other ways that the ancestral, animalistic parts of our brain affect the way we see the world, filter information and make decisions about how to spend our money or whom to trust. Understanding our limitations, he says, will help us get the most out of our “klugey” brains, and in his final chapter he offers a number of suggestions.
For example, he says to beware vivid, personal data: A friend may have had a pregnancy scare after a particular brand of condom broke during intercourse, but a statistically robust study would still tell you that condoms are generally reliable. Your brain’s attraction to the dramatic anecdote means that intuition can lead you astray.
These conclusions are based almost entirely on studies conducted by other scientists, not Dr. Marcus himself – who (like his Canadian-born wife, Athena Vouloumanos) studies how babies learn language, one of the things the human brain does incredibly well.
His book could be criticized by scientists who study parts of the brain that are anything but haphazard – the precise neural networks involved in seeing and hearing, for example. But Dr. Marcus says he is a theoretical cognitive scientist, someone who puts together the big picture about how the brain works. To do that, he says, he needs to consider both the unparalleled power of the human brain and what he describes as the bugs in our cognitive makeup.
His work has made him conscious about how his own brain works, and he tries to take his own advice – not that he always succeeds. If his dining companion orders crème brûlée, he usually ends up getting one too.
Anne McIlroy is The Globe and Mail’s science reporter.
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