Weird But True (14 page)

Not Dead
Yet

J
ust when they thought they could wipe out certain types of harmful bacteria, medical researchers discovered some that simply refuse to die. These are known as “persisters” because they seem to resist all the antibiotic treatments that should kill them. Instead, persisters go into a dormant state—playing dead without actually dying—so that someday, under the right (or wrong!) conditions, they can come alive again.

Do as I Say,
Not as I Do

N
inety-two percent of Americans say that they wash their hands after using public restrooms; observational research says that only 77 percent actually do.

And That's
the Truth

A
2002 study at the University of Massachusetts found that 60 percent of people lied at least three times in a ten-minute casual conversation.

* * *

The same study found that while men and women lie with about the same frequency, men lie to make themselves look better, appear more likable, or seem more competent, while women lie to make others feel better.

Department of
Hair-Splitting

T
he college professor who wrote the definition of lying for the
Stanford
Encyclopedia of Philosophy
contends that an untrue statement isn't a lie unless the person telling it knows that it's false and says it anyway, with the intention to deceive another person.

So, if you believe something, it's not a lie.

Your Lying
Smile

H
ow can you tell whether someone who is smiling really means it? The answer lies in the eyes. The genuine human smile—the one that comes uncontrolled when you're truly happy or amused—is known as the Duchenne smile. It's named for a nineteenth-century French neurologist who determined that a fake smile is one that uses only the muscles surrounding the mouth, but a genuine smile engages the muscles around the eyes forming “crow's feet”—which ordinarily doesn't make people happy, but in this case perhaps we'll make an exception.

* * *

There is some evidence that people who smile genuinely most often tend to live longer.

A Lie of
the Mind

W
hen you lie, your brain increases blood flow to the prefrontal cortex, the part of the brain that you use for making decisions, concocting stories, and distinguishing between right and wrong— the things you have to think about. When you tell the truth, your response tends to be automatic. You can answer without thinking, so the brain does not exhibit the same type of blood flow response.

Brain
Drain

O
ver the past several thousand years human brains have gotten smaller. Anthropologists recreated the brain that would have fit inside a Cro-Magnon skull discovered in France. That 28,000-year-old brain would have been nearly 20 percent larger than today's human brain.

Remembrance
of Places
Passed

I
f you have a great sense of direction, thank the neurons in your brain. Neurons known as “path cells” help you remember the direction you were traveling when you spotted a particular landmark. A separate set of neurons, known as “place cells,” help you remember a place you've been. Together they work to get you where you want to go.

This Looks
Familiar

M
agellanic penguins migrate by swimming from their homes in southern Chile and Argentina hundreds of miles north to the coast of Brazil each winter. They return to their birthplace for the mating season every spring.

Haven't We
Been Here
Before?

S
tudies have found that at least 60 percent of people (probably more) have experienced a sense of déjà vu. Episodes of déjà vu tend to decrease as you age.

* * *

Déjà vu does not require visual cues: Blind people experience déjà vu as often as sighted people.

Repeat
That

K
arl Marx is often credited with coining the phrase “History repeats itself.” However, he didn't actually write those words, and he never claimed them as his own.

The general idea came from a treatise written by the German philosopher Georg Wilhelm Friedrich Hegel. The politcal philosopher Friedrich Engels, Marx's friend and colleague, paraphrased Hegel's idea in a letter he wrote to Marx, and Marx later paraphrased it again in a pamphlet he wrote about French politics.

Never Seen
That Before

N
o two bolts of lightning are identical.

Been There,
Done That

C
entral Africa experiences more lightning strikes than anyplace else on the planet. Lightning almost never strikes in the Arctic or Antarctica.

* * *

With hundreds of millions of lightning strikes on the planet every year—twenty million in the continental United States alone—there's no reason for scientists to believe that lightning can't strike the same place twice. In fact, they're pretty certain that it does.