"When our son-in-law, Salvador, visited the United States for the first time, we drove around my hometown to show him a bit of Middle America. Nearing my bank, I remembered that I needed some cash and entered the lane for the ATM machine," writes psychologist Madeline Van Hecke in her book, "Blind Spots."
"While we waited for the transaction to be processed, I gestured toward the monitor and bragged to Salvador, 'We've become more sensitive to the needs of handicapped people in the United States. See the directions for the ATM machine written in Braille?'
"I was feeling proud of the sensitivity our bank demonstrated with this feature. Salvador laughed at me.
" 'What's so funny?' I asked with irritation.
'How many blind drivers do you have in this city?' he replied.
"The Braille instructions that I had pointed out with such pride just moments earlier now appeared totally idiotic."
She grasped at straws, arguing that a sighted driver could be driving a blind person to the bank, but she knew deep down, she confesses, that it didn't make much sense to have Braille instructions at a bank drive-through. It does make sense to use Braille to mark the floors in an elevator.
She felt foolish. Salvador's point was so obvious. How could she, a highly educated Ph.D., have missed it?
Most of the time our minds work pretty well. But sometimes smart people do stupid things, she points out. We have a systematic set of "blind spots" in our minds like the blind spots in our cars.
We are amused by cartoons like "Dilbert," which make them obvious and exaggerate them: "As of tomorrow, employees will only be able to access the building using individual security cards. Pictures will be taken next Wednesday and employees will receive their cards in two weeks."
But even in easy tests of mental reasoning, we often fail to be logical. Psychologists Benjamin Connell and M.D. Braine in an article in Developmental Psychology did an interesting experiment that shows how easy it is to make a mistake.
Try it yourself. I flunked it the first time.
The researchers held a box and told the person being tested, "If there's a cat in the box, there's also an apple in the box."
Next he would look in the box himself and say, "There's a cat in the box. Is an orange in the box?"
Half of the adults answered "no." They had failed to grasp the simple point that an orange could be in the box, not just an apple and a cat.
After a number of similar examples, the adults caught on. But the experiments had to present such problems five times on average before they did.
Curiously, 4-year-olds solved this type of problem as well as the adults did.
That a child can reason in some situations as well as an adult makes the adult's mistakes more intriguing.
One of the blind spots Van Hecke identifies is the way we are "lulled by everyday life." We don't stop and think, like the example of the Braille sign in a drive-by bank. Sure, the law may insist that we use Braille in some situations. But we don't ordinarily notice that these practices make no sense.
Another type of blind spot is rushing in to solve a problem without "stopping to think." That's what happened to so many adults in the cat-apple-orange experiment. Adults rarely have to solve such straightforward logical puzzles.
How can we avoid such intellectual blunders? First, be aware of the errors you are prone to, says Van Hecke. Car manufacturers, for example, routinely put a warning on the side-view mirrors, "Objects may be closer than they appear."
We don't need such warnings most of the time. Indeed, if you Google "blind spots cars," you can find ways to minimize the blind spots. We can usually rely on experience, expertise and, yes, often our intuition to solve problems. But when we have important problems to solve, Van Hecke's work shows, we need to step back, take our time, and carefully think.
Judith Kleinfeld, who holds a doctorate from Harvard, is professor of psychology emeritus at the University of Alaska Fairbanks.