Ever noticed that when you stare at your fingers for long enough they start transforming into alien appendages before your very eyes? You see the mundane for what it really is: freaky-looking.
The same goes for the rest of our traits. We take for granted that funny things make us yell out spastically — also known as laughing — and that we spend one-third of every day in a deathlike state of suspended animation known as sleep. But with a little contemplation, these behaviors seem truly bizarre.
Here are 10 mundane yet weird things we do all the time, and why we do them.
How odd that sadness causes water to spill from our eyes! Among all animals, we alone cry tears of emotion.
Not only do they serve the purpose of communicating feelings of distress, scientists believe tears also carry certain undesirable hormones and other proteins that are produced during periods of stress out of the body, which may explain the cathartic effect of “a good cry.”
Hiccups are involuntary spasms of the diaphragm — the muscular membrane in your chest that figures importantly in breathing. A spell of them ensues when that muscle gets irritated, often by the presence of too much food in the stomach, or too little.
Weirdly, though, hiccups are as useless as they are annoying; they serve no apparent purpose. One hypothesis suggests they may be a remnant of a primitive sucking reflex. Whatever the ancient function, they are little more than a nuisance now — something to be gotten rid of via a variety of creative folk remedies.
What Causes Hiccups?
A hiccup is a contraction of your diaphragm, the muscular membrane in your chest that figures importantly in breathing. Inhaling contracts the diaphragm and exhaling relaxes it.
Hiccups are spasmodic, involuntary, and as useless as they are annoying. A post-Thanksgiving distended stomach can irritate the diaphragm and cause a fitful spell of hiccups. Exercise or stress can cause them as well. More often, though, the reflex has no apparent cause.
One hypothesis suggests that hiccups may be a remnant of a primitive sucking reflex. Whatever the ancient function, they are little more than a nuisance now. And everyone swears they’ve got the surefire cure, whether it’s holding your breath, giving yourself a good scare, sucking on grains of sugar, drinking water upside down or even (one reputable journal reports) a gentle, modified Heimlich maneuver. Many of these actually work, by temporary halting the rhythm of respiration.
We spend roughly one-third of our lives asleep. No human can go without it for more than a handful of days, and yet sleep may be the least understood of all our activities.
It certainly allows for a lot of body “maintenance work,” from production of chemicals that get used during waking hours to the self-organization of neurons in the developing brain. REM sleep, with its high neuronal activity, occurs for longer each night during periods of brain growth.
Several theories point to sleep as a state vital to memory and learning. It may help ingrain episodic memories into long-term storage, and it also may simply give our mental waking activities a much-needed break.
How Are Memories Stored in the Brain?
Because memories underlie so much of our rich life as humans — our ability to learn, to tell stories, even to recognize each other — it’s unsettling to think that it all hinges on the mass of flesh and goo between our ears.
Researchers have been able to trace memory down to the structural and even the molecular level in recent years, showing that memories are stored throughout many brain structures in the connections between neurons, and can even depend on a single molecule for their long-term stability.
Do Colorblind People Dream In Color?
Although researchers previously believed that dreams were only black and white, they now know that most dreams are colorful. But how do the dreams of colorblind people look?
That depends on when they became colorblind. Because humans dream about what they know, people who become colorblind after birth can “see” colors in their dreams, according to “Colour Blindness: Causes and Effects” (Dalton Publishing, 2002).
However, people who are born completely colorblind and can only see their surroundings in black, white and shades of gray, do not know what colors look like, and therefore, their minds have no memories from which to fabricate colorful dreams.
Complete colorblindness, a visual condition also known as total color vision deficiency (CVD) or achromatopsia, is extremely rare and affects only an estimated one in 30,000 people worldwide, according to the National Library of Medicine (NLM).
Red-green color vision defects (in which a person has trouble distinguishing between reds and greens) are much more common and make up about 99 percent of color vision defieiencies, according to “Colour Blindness: Causes and Effects.” Among populations with Northern European ancestry, red-green color vision defects occur in about 8 percent of males and 0.5 percent of females, according to the NLM.
A person with a red-green color vision defect will dream in the same color set that they see when awake. For example, in his or her dreams, the American flag will have moss-green stripes instead of scarlet.
In the 1950s, dream researchers commonly believed that people only dreamt in black and white, even though both previous and later dream research studies established that dreams have color, according to a 2002 study by Eric Schwitzgebel, a philosophy professor at the University of California at Riverside.
The growing popularity of black and white films in the 1950s as well as increased affordability of black and white television sets may have played a role in the phenomenon of people with full sight having colorblind dreams.
“The first half of the twentieth century saw the rise of black and white film media, and it is likely that the emergence of the view that dreams are black and white was connected to this change in film technology,” Schwitzgebel stated in his study, which appeared in the journal Studies in History and Philosophy of Science.
In the 1960s, as media began to shift to full color, reports of black and white dreams became increasingly rare, showing that the things people observe during the daytime leach into their dreamscape.
“Only very, very rarely does someone report a dream that is black and white like an old movie,” said Deirdre Barrett, a psychologist at Harvard Medical School who is an expert on dreaming.. “If they’re not color blind, this may be due to exposure to old films.”
Barrett notes that if you can’t remember the colors in last night’s dreams, that doesn’t necessarily mean that you dreamt in black and white. Some people may focus on the colors within a dream, while others don’t notice what color things were. This selective perception of sorts is similar to how different people perceive the real world, Barrett said.
“If I asked you to describe something that happened two days ago, you might include no color in the incident – or you might,” Barrett told Life’s Little Mysteries. “If I asked you what color someone was wearing, you might be able to tell me or not—color just isn’t always a salient part of events. The events may be more about the interpersonal aspect, such as navigating or trying to get somewhere, while at other times, color is significant to whatever we’re doing and noticing.”
Okay, technically speaking, dying isn’t an everyday activity. It is, however, done by a whole bunch of people every day. Why?
We die because our cells die. Though they replace themselves over and over again for 70-odd years, they can’t do so forever. Inside each cell, telomeres at the end of our chromosomes contain genetic information that gets clipped away with each cell division. Telomeres start out long enough to handle a great many scissor snips. But eventually, they run out of length, the information they held is lost and the cells can’t divide anymore.
Luckily, scientists are working on how to extend the lives of human beings, and think they could someday double the average lifespan.
Toward Immortality: The Social Burden of Longer Lives
Adam and Eve lost it, alchemists tried to brew it and, if you believe the legends, Spanish conquistador Juan Ponce de Leon was searching for it when he discovered Florida.
To live forever while preserving health and retaining the semblance and vigor of youth is one of humanity’s oldest and most elusive goals.
Now, after countless false starts and disappointments, some scientists say we could finally be close to achieving lifetimes that are, if not endless, at least several decades longer. This modern miracle, they say, will come not from drinking revitalizing waters or from transmuted substances, but from a scientific understanding of how aging affects our bodies at the cellular and molecular levels.
Whether through genetic tinkering or technology that mimics the effects of caloric restriction—strategies that have successfully extended the lives of flies, worms and mice—a growing number of scientists now think that humans could one day routinely live to 140 years of age or more.
Extreme optimists such as Aubrey de Gray think the maximum human lifespan could be extended indefinitely, but such visions of immortality are dismissed by most scientists as little more than science fiction.
While scientists go back and forth on the feasibility of slowing, halting or even reversing the aging process, ethicists and policymakers have quietly been engaged in a separate debate about whether it is wise to actually do so.
A doubled lifespan
If scientists could create a pill that let you live twice as long while remaining free of infirmities, would you take it?
If one considers only the personal benefits that longer life would bring, the answer might seem like a no-brainer: People could spend more quality time with loved ones; watch future generations grow up; learn new languages; master new musical instruments; try different careers or travel the world.
But what about society as a whole? Would it be better off if life spans were doubled? The question is one of growing relevance, and serious debate about it goes back at least a few years to the Kronos Conference on Longevity Health Sciences in Arizona.
Gregory Stock, director of the Program on Medicine, Technology, and Society at UCLA’s School of Public Health, answered the question with an emphatic “Yes.”
A doubled lifespan, Stock said, would “give us a chance to recover from our mistakes, lead us towards longer-term thinking and reduce healthcare costs by delaying the onset of expensive diseases of aging. It would also raise productivity by adding to our prime years.”
Bioethicist Daniel Callahan, a cofounder of the Hastings Center in New York, didn’t share Stock’s enthusiasm. Callahan’s objections were practical ones. For one thing, he said, doubling life spans won’t solve any of our current social problems.
“We have war, poverty, all sorts of issues around, and I don’t think any of them would be at all helped by having people live longer,” Callahan said in a recent telephone interview. “The question is, ‘What will we get as a society?’ I suspect it won’t be a better society.”
Others point out that a doubling of the human lifespan will affect society at every level. Notions about marriage, family and work will change in fundamental ways, they say, as will attitudes toward the young and the old.
Marriage and family
Richard Kalish, a psychologist who considered the social effects of life extension technologies, thinks a longer lifespan will radically change how we view marriage.
In today’s world, for example, a couple in their 60s who are stuck in a loveless but tolerable marriage might decide to stay together for the remaining 15 to 20 years of their lives out of inertia or familiarity. But if that same couple knew they might have to suffer each other’s company for another 60 or 80 years, their choice might be different.
Kalish predicted that as life spans increase, there will be a shift in emphasis from marriage as a lifelong union to marriage as a long-term commitment. Multiple, brief marriages could become common.
A doubled lifespan will reshape notions of family life in other ways, too, says Chris Hackler, head of the Division of Medical Humanities at the University of Arkansas.
If multiple marriages become the norm as Kalish predicts, and each marriage produces children, then half-siblings will become more common, Hackler points out. And if couples continue the current trend of having children beginning in their 20s and 30s, then eight or even 10 generations might be alive simultaneously, Hackler said.
Furthermore, if life extension also increases a woman’s period of fertility, siblings could be born 40 or 50 years apart. Such a large age difference would radically change the way siblings or parents and their children interact with one other.
“If we were 100 years younger than our parents or 60 years apart from our siblings, that would certainly create a different set of social relationships,” Hackler told LiveScience.
For most people, living longer will inevitably mean more time spent working. Careers will necessarily become longer, and the retirement age will have to be pushed back, not only so individuals can support themselves, but to avoid overtaxing a nation’s social security system.
Advocates of anti-aging research say that working longer might not be such a bad thing. With skilled workers remaining in the workforce longer, economic productivity would go up. And if people got bored with their jobs, they could switch careers.
But such changes would carry their own set of dangers, critics say.
Competition for jobs would become fiercer as “mid-life re-trainees” beginning new careers vie with young workers for a limited number of entry-level positions.
Especially worrisome is the problem of workplace mobility, Callahan said.
“If you have people staying in their jobs for 100 years, that is going to make it really tough for young people to move in and get ahead,” Callahan explained. “If people like the idea of delayed gratification, this is going to be a wonderful chance to experience it.”
Callahan also worries that corporations and universities could become dominated by a few individuals if executives, managers and tenured professors refuse to give up their posts. Without a constant infusion of youthful talent and ideas, these institutions could stagnate.
Hackler points out that the same problem could apply to politics. Many elected officials have term limits that prevent them from amassing too much power. But what about federal judges, who are appointed for life?
“Justices sitting on the bench for a hundred years would have a powerful influence on the shape of social institutions,” Hackler writes.
Time to act
A 2003 staff working paper drawn up by the U.S. President’s Council of Bioethics—then headed by Leon Kass, a longtime critic of attempts to significantly extend the human lifespan—stated that anti-aging advances would redefine social attitudes toward the young and the old, and not in good ways.
“The nation might commit less of its intellectual energy and social resources to the cause of initiating the young, and more to the cause of accommodating the old,” the paper stated. Also, quality of life might suffer. “A world that truly belonged to the living would be very different, and perhaps a much diminished, world, focused too narrowly on maintaining life and not sufficiently broadly on building the good life.”
While opinions differ wildly about what the ramifications for society will be if the human lifespan is extended, most ethicists agree that the issue should be discussed now, since it might be impossible to stop or control the technology once it’s developed.
“If this could ever happen, then we’d better ask what kind of society we want to get,” Callahan said. “We had better not go anywhere near it until we have figured those problems out.”
Do Hair and Nails Keep Growing After Death?
As creepy as a “yes” would be, the answer is maybe an even creepier “no”.
After death, the human body dehydrates, causing the skin shrink back, which exposes the part of the nails and hair that was under the skin, causing them to simply appear to grow.
See in 3-D
Hey, wait a second… how do two eyes produce 3-D vision?
It’s actually a trick of the mind (or three tricks, to be exact). First, our brains utilize “binocular disparity” — the slight difference between the images seen by our left and right eyes. Our brains use the two skewed versions of a scene to reconstruct its depth.
For a close-up object, the brain registers the “convergence” of our eyes, or the angle they swing through to focus on the object, to decide how far away it is.
When glancing at things on the go, we subconsciously gauge distance by registering “parallax.” That’s the difference in speed at which closer and farther objects seem to move as you pass them.
Why Do We See in 3-D?
When it comes to seeing in 3-D, two eyes are better than one. To see how 3-D vision works, hold a finger at arm’s length and look at it through one eye, then through the other. See how the image seems to jump? That’s because of binocular disparity, the slight difference between the images seen by each eye.
Binocular disparity is one of the most important pieces of information the visual centers of the brain use to reconstruct the depth of a scene.
If the object you’re trying to view is close to you, the brain uses another clue: convergence, or the angle of your eyes as you focus on an object. Crossing your eyes will give you an extreme example of the convergence sensation.
But even without binocular vision, it’s possible to judge depth. Animals without overlapping visual fields rely heavily on something called parallax, which is the difference in speed at which closer and farther objects seem to move as you pass them. For example, fence posts along the side of a highway will fly by, while a grain silo a quarter-mile from the road will seem to creep. Our brain has a built-in processing center for this phenomenon, according to a 2008 Nature study. An area behind the ear called the middle temporal region carries information about parallax, and may synthesize it with other depth cues.
Other means of perceiving depth using just one eye involve cues including object size, parallel lines that appear to converge, sharper textures in closer objects, and the way objects overlap.
Even with all these cues at its disposal, the brain makes mistakes. Artists can trick the brain into seeing a 2-D painting in three dimensions by drawing converging parallel lines and painting “closer” objects in greater detail.
Gym class can be a bummer for the visual system, as well: According to a 2008 study in the journal Proceedings of the National Academy of Sciences, our brains take shortcuts based on previous experience when judging depth. Because most objects we encounter move relatively slowly, we may misjudge the distance of fast-moving objects — like a soccer ball headed for our face.
Turns out, the cheek-reddening reaction is a universal human response to social attention. Everyone does it — some more than others. Common blushing
triggers include meeting someone important, receiving a compliment and experiencing a strong emotion in a social situation.
Blush biology works like this: Veins in the face dilate, causing more blood to flow into your cheeks and producing a rosy complexion. However, scientists are stumped as to why all that happens, or what function it serves.
It’s weird, when you think about it, that swapping spit seems romantic. Turns out it’s a biological instinct.
Kissing allows people to use smell and taste to assess each other as potential mates. People’s breath and saliva carry chemical signals as to whether they are healthy or sick, and in the case of females, whether they’re ovulating — all important messages for potential partners in reproduction.
Furthermore, the skin around peoples’ noses and mouths is coated with oils that contain pheromones, chemicals that broadcast information about a person’s biological makeup. When people pick up each other’s pheromones during a sloppy kiss, they’ll subconsciously become either more or less sexually attracted to each other depending on what they detect.
Alongside the chemosensory cues exchanged during kisses, psychologists also believe the actual physical act of kissing helps couples bond. This theory is supported by the fact that oxytocin — a hormone that increases most peoples’ feelings of sociality, love and trust — floods brains when mouths kiss.
Love Is Scary: 12 Weird Phobias
Romance can be pretty anxiety-inducing. From the fear of staying single to a dread of chocolate, Life’s Little Mysteries has rounded up the strangest love-related phobias. Here are a dozen examples:
1. “Commitmentphobia” is a made-up phobia, but folks who fear being in a relationship may actually have amoraphobia, the fear of love.
2. People with metrophobia, the fear of poetry, would need to hire a ghostwriter if they want to pen their sweetheart a passionate verse.
3. A heart-shaped box of chocolates — that sweet Valentine’s Day staple — would be more horrifying than romantic to those with xocolatophobia, the fear of chocolate.
4. Here’s a phobia that is probably most common among bashful people making an overture to a crush: Erythrophobia, or fear of blushing, causes the sufferer to be extremely embarrassed and self-conscious of their reddening complexion. Talk about a vicious cycle.
5. Anyone who has ever been the victim of a particularly bad kisser can understand philematophobia, or the fear of kissing.
6. Sending a red, heart-shaped Valentine’s Day card to someone with cardiophobia, the fear of the heart, would be a pretty cruel thing to do.
7. What could possibly be threatening about a bouquet of flowers? Among those with anthrophobia, or the fear of flowers, a single red rose brings about feelings of anxiety — even if it’s been de-thorned.
8. People with haphephobia or aphenphosmphobia must get pretty lonely, as their phobias cause them to avoid letting anyone touch their skin.
9. Headaches caused by overwhelmingly strong, chemical scents and burns from hot wax may explain why some suffer from keriophobia — the fear of candles.
10. Guys who have anuptaphobia, the fear of staying single, might want to use a wingman to help pick up women at bars.
11. & 12. These last two go together: Ornithophobia, the fear of birds, and apiphobia, the fear of bees. One poses the threat of being pooped on from above and the other packs a painful sting, so these phobias seem pretty reasonable to us.
The answer may stink, but everything we eat or drink gives us gas. In fact, it’s normal to fart up to half a gallon (1.9 liters), or about 15 to 20 toots worth of gas each day.
Particularly fragrant flatulence, however, comes from colonies of bacteria shacked up inside our lower intestinal tract. In the process of converting our meals into useful nutrients, these food-munching microbes produce a smelly by-product of hydrogen sulfide gas—the same stench that emanates from rotten eggs.
Just like the rest of us, the bacteria like munching on sugary foods best. The types of sugar naturally present in milk, fruit — and, of course, beans — produce the most farts.
The punchline of a joke hits you, and with it comes a funny feeling: You’re suddenly overcome by the urge to yell out spastically, over and over. Laughing is weird. Why do we do it?
Psychologists think this behavioral response serves as a signal to others by spreading positive emotions, decreasing stress and contributing to group cohesion. For those same reasons, chimps and orangutans smile and laugh during social play too.
In fact, many hypothesize that laughing evolved from panting. When our prehuman ancestors wrestled playfully with each other, they got all panty… and that eventually turned into getting laughy.
It’s not that strange that we blink: The tenth-of-a-second-long activity clears away dust particles and spreads lubricating fluids across the eyeball. What is strange, though, is that we fail to notice the world plunging into darkness every two to 10 seconds!
Scientists have found that the human brain has a talent for ignoring the momentary blackout. The very act of blinking suppresses activity in several areas of the brain responsible for detecting environmental changes, so that you experience the world around you as continuous.