The human body is an amazing machine that is more complex than any man-made device ever created. While many of the functions it carries out require little explanation, some things it does are more complex. For the most part, people have no idea why their body does these things, but scientists and researchers have investigated them and came up with simple explanations for the baffling everyday functions of our body.

10Hiccups

Everyone has hiccuped at some point in their life. However, the involuntary action usually comes and goes relatively quickly for the vast majority of people, meaning it is more of a nuisance than anything else. Although for some, it can become something of an issue. Charles Osborne, for example, had the hiccups for 68 years.

Scientists have never been able to completely understand why people hiccup, but they have proposed several theories. One of the most recent ones comes from Daniel Howes. He suggests that the hiccups may have evolved as a way for infants to expel air from the stomach so that they can more effectively suckle milk. The contraction of the diaphragm causes suction that forces air out of the mouth, allowing the infant to burp itself. Howes points to the fact that only mammals—the only type of animals that suckle milk—get hiccups and that they are much more prevalent in the young.

9Appendix

The appendix has long been considered an organ that does more harm than good. Its function was a mystery, and it has a tendency to cause serious health problems in a number of people. Appendicitis can lead to severe pain, fever, and even death if it is left untreated after the appendix bursts.

In 2007, after years of research, researchers finally discovered what’s believed to be the actual use of the appendix. Rather than simply being a leftover organ from our evolutionary past, it was an important part of the immune system. According to the research team, the appendix provides a safe haven for bacteria that is needed in the gut. When illness or diseases such as dysentery wipe out the bacteria in the gut, the organ allows the bacteria to reenter the digestive system. It essentially keeps a backup of bacteria needed for the immune system to function.

8Tickling

Every person has experienced being tickled at some point. While it can be pleasant at times, it is usually something that people dislike and try to avoid. This has never stopped people from trying to tickle others, though. That fact, combined with the response to tickling, is something that has perplexed thinkers for thousands of years.

Previously, it had been thought that the reaction might be a panic response, similar to that triggered by a spider crawling on you. But Christine Harris, following numerous experiments, has suggested a more complex answer. According to Harris, tickling may be a system designed to help develop combat skills.

She points to the fact that close family members or friends usually carry out that tickling in much the same way as play fighting. It causes the recipient to convulse and try to break free as quickly as possible, teaching the victim how to get away from an attacker without actually causing them any harm. Meanwhile, the fact that the recipients laugh and smile when being tickled encourages the tickler to carry on the action and to do it more frequently. This increases the value of the action as it is reinforced multiple times.

7Wrinkled Fingers And Toes

Spending a long time in the water will lead to fingers and toes becoming wrinkled. This bodily function has baffled researchers for decades, with very little evidence to say definitively what the cause of the reaction was. A leading theory had been that water caused the skin to swell, leading to the wrinkling effect.

Scientists now believe they have come up with the exact reason. According to a number of researchers, the wrinkling is an evolutionary advantage that helps to increase grip in wet conditions. Experiments showed that those with wrinkled fingers and toes get a better grip on wet objects.

Another study from Newcastle University theorized that the function might have helped our ancestors handle tools in rainy conditions or have steadier footing on a soaked floor, providing an advantage over others who did not get wrinkly fingers and toes from water.

6Lump In Your Throat

Ever been really sad and felt a lump in your throat even though you knew for a fact that there’s nothing physically there? That’s a pretty common occurrence that happens to people when they get bad news or are on the verge of crying.

The “lump in the throat” sensation is a consequence of the fight-or-flight response inbuilt in humans, which is induced when a person is put in danger or under intense stress. In these emotional situations, the body pumps blood and oxygen to the brain and muscles to allow it to react faster. This has the added effect of causing the heart to pump harder and for breathing to become more frequent. To facilitate this, vocal chords, known as the “glottis,” expand to allow more air to pass through the throat. However, when a person tries to swallow, the glottis need to close. The muscles effectively work against each other, causing the “lump” sensation.

5Phantom Vibration Syndrome

If you use a smartphone or another electronic device that comes with a vibrate function, you will probably have experienced the “phantom vibration syndrome.” Essentially, you feel a vibration in your pocket, take out the phone, and see that your phone is dark. Nothing has happened to cause the device to vibrate, and yet you could clearly feel it.

In 2010, a study found that 68 percent of people using such devices experience these phantom vibrations on a regular basis. Possible explanations include the brain misinterpreting other sensory information, such as a slight movement in clothing, as vibration as it anticipates incoming communication through the device.

4Shiver Down The Spine

Shivers down the spine, and the goosebumps that traditionally accompany them, happen in all kinds of situations. They usually occur during stressful moments, such as when a person is in danger. This affects the hypothalamus, the section of the brain that controls certain nervous system functions. It releases large amounts of adrenaline to help the body prepare to react to the situation. This causes muscles to contract and hair to stand on end, leading to goosebumps. The same reaction happens when a person feels intense emotions such as love, happiness, or shock. Music causes shivers down the spine because it induces strong emotions in humans, causing the brain to release adrenaline.

3Yawning

The act of yawning is so contagious that even reading about it can cause a person to yawn, but there has been much debate over what exactly causes it. One competing theory was that yawning allows the body to take in more oxygen for stressful events that are about to occur, like in sports, to make the body more alert. Other theories suggested that it may be a way to communicate boredom and tiredness and to pump vital fluid around the body.

In 2014, researchers came up with a new theory that unified many of the contradictory elements of yawning to give a complete explanation. According to the study, yawning is the body’s way of attempting to cool down the brain. The yawn takes cold air in and increases blood flow around the brain, carrying away excess heat. This theory also explains why so many situations cause yawning. The brain heats up in stressful situations and before exercise; it also increases in temperature as people grow tired. Yawns fight boredom by allowing the brain to be more alert.

2Alcohol-Induced Blackouts

It is a fairly common occurrence for those who have drunk a large amount of alcohol to be unable to remember parts of a night out (or the entire event). While these blackouts can happen with other drugs, they happen most frequently with alcohol.

Studies have shown that alcohol prevents the brain from being able to transfer short-term memory to long-term memory, essentially stopping people from remembering recent events. This is because alcohol stops receptors in the hippocampus from releasing glutamate. This prevents neurons from being able to communicate with each other normally, blocking the transfer of memory. As such, the person becomes unable to create new memories. The memory can still exist somewhere in the brain, though, which explains why people can be reminded of an event from the previous night and then suddenly remember all about it.

1Seasickness

Seasickness, and other types of motion sickness, is a set of symptoms experienced by a large amount of people when they are traveling in vehicles such as ships and cars. The symptoms can include vomiting and dizziness.

It happens because of a disconnect between what a person feels and sees. On a rocking boat, for example, the body senses the motion through the inner ear but cannot see the movement, as the entire boat appears to be still. This causes the brain to receive conflicting information. This triggers a psychological defense mechanism, because the most likely cause of a conflict between the senses are hallucinations brought about by poison. The nausea and vomiting are the body’s way of trying to get rid of the toxins it thinks are affecting it.

While medication and electronic devices can prevent seasickness, it can also be mitigated by looking at the horizon on a boat or out of the window in a car. This gives the eyes a visual cue to sense the motion, and so the brain doesn’t receive confusing information.

Nathan is a freelance writer who has provided work for a number of websites across a variety of topics including film, TV, sports, video games, and humor. He also occasionally writes serious pieces. You can keep up to date with his work at his website.

There is very good reason for all of humanity to have a healthy curiosity relating to near-death experiences. Death is the one experience we are all guaranteed to ultimately share. The field of science has therefore made numerous attempts to explain the near-death phenomena that so many people have independently described.

10The Temporoparietal Junction May Be Responsible For Out-Of-Body Experiences

Among the more common elements of near-death experiences is the distinct feeling of an individual having left their worldly body. Those who have had an “out-of-body” experience often report floating above themselves while being able to see their body and the people surrounding them. There have even been a few reports in which those who have had an out-of-body experience can identify objects and events occurring during times in which they were considered clinically dead, but there have also been studies demonstrating that this all could be due to damage in the temporoparietal junction of the brain.

The temporoparietal junction is responsible for assembling the data collected by the body’s senses and organs to form the perception of an individual’s body. When this part of the brain is damaged, it is possible that this results in the “out-of-body” experience that so many people have reported.

Though the experience may appear to be incredibly vivid and real, scientific studies have been able to reproduce this phenomenon without bringing the subject close to death, simply by electrically stimulating the temporoparietal junction of the brain.

9Excess Carbon Dioxide May Create The Tunnel And White Light

Nearly every individual who has had a near-death experience discusses the existence of a bright, white light and a tunnel that seems to lead to the afterlife. The white light seems to take on an otherworldly quality and is often accompanied by an overwhelming sense of peacefulness and welcoming.

A 2010 study of patients who had heart attacks revealed that there may be a correlation between this type of near-death experience and the level of CO₂ in the blood. Out of the 52 cardiac patients studied, 11 reported a near-death experience. The levels of CO₂ in the blood of those 11 patients were significantly higher than the patients who did not report having a near-death experience.

The feeling among researchers is that the excess CO₂ in the bloodstream can have a significant effect on vision, which leads to patients seeing the tunnel and the bright light.

8Lack Of Oxygen To The Brain Causes Hallucinations

Many near-death experiences include the presence of long-dead friends and relatives appearing and perhaps even guiding the individual as they pass from the world of the living to the afterlife. Memories from every part of life are recalled in rapid succession, and there is an overwhelming sense of comfort, yet it appears that scientific research has provided an explanation for this phenomenon as well.

While excess CO₂ has an effect on vision during a near-death experience, a lack of oxygen to the brain also plays a contributing role. It is well known that oxygen deprivation can lead to hallucinations and may even contribute to the feeling of euphoria that is often reported. While the sample size available to researchers is limited, studies have indicated that individuals who reported a near-death experience during cardiac arrest also had lower levels of oxygen.

Researchers believe that oxygen deprivation could well result in people “seeing their lives flash before their eyes” or being transported to a place where they are surrounded by friends and relatives who have long since passed on. This remains just a theory, however, as the other available research seems to indicate that multiple factors contribute to the near-death experience, which include the aforementioned CO₂ levels as well. It makes sense in this regard that near-death experiences are commonly reported by those resuscitated following a heart attack, as a heart attack occurs when blood is blocked from reaching the brain.

7Endorphins Are Released When The Brain Is Under Extreme Stress

It has been a long-held theory that much of what is felt during a near-death experience can be somewhat attributed to the release of endorphins and other chemicals by the brain due to extreme stress. While the idea that the entirety of a near-death experience could be attributed to endorphins has been somewhat dispelled, it could easily explain why so many individuals who have had a near-death experience feel no fear or anxiety over reaching life’s apparent terminus.

The release of these morphine-like chemicals during times of extreme stress was proposed by neuropsychologist Daniel Carr as an overarching explanation for near-death experiences, but it appears that it better explains the calm sensations and the lack of pain or worry during situations in which the body could be under extreme duress. So while you’d expect that in the stages approaching death, there would be “incredible pain and terror, the [near-death experience] surprises us with pleasure, calm, and peace,” a phenomenon believed to be the result of chemicals released by the brain.

6Brain Activity Spikes In The Moments Before Death

Heightened sensory perception is common in the near-death experience, and a recent study seems to indicate that these feelings of extrasensory perception may be caused by a significant spike in brain activity in the moments just before death. The study was conducted on rats and used a small sample size, so some in the scientific community have dismissed the results, but lead researcher Jimo Borjigin believes that it demonstrates the biological basis for the near-death experience.

The study relied on the implantation of electrodes into the brains of the rats so that researchers could study the levels of brain activity at the time of death. The results showed that the rats experienced what the researchers termed as “hyperconsciousness,” which aligns with the heightened senses many individuals associate with a near-death experience. According to Borjigin, “We found continued and heightened activity. Measurable conscious activity is much higher after the heart stops—within the first 30 seconds.”

5Veridical Perception May Be Confused With Anesthesia Awareness

Veridical perception (the out-of-body experience) may be rooted in a cause other than the aforementioned damage to the temporoparietal junction. Many out-of-body experiences may be nothing more than anesthesia awareness. Though awareness while under anesthesia is thankfully quite uncommon (about one in every 1,000 people experience it), it is possible that those who believe that they have had a near-death experience are simply constructing false memories through this awareness.

This may be the underlying reason that Pam Reynolds, whose near-death experience is often referenced, was able to recall so many details of an operation that involved inducing “hypothermic cardiac arrest,” rendering her effectively dead for several minutes. Reynolds was able to describe the shape of the saw used to cut open her skull and even recognized that the doctors were listening to the song “Hotel California” during the operation.

Reynolds’s near-death account seems like very powerful evidence of a near-death experience that includes veridical perception, but everything she recalled occurred while she was alive but under anesthesia. So while Reynolds may have thought she had a near-death experience, skeptics believe that this was more likely one of the rare cases in which a patient experienced anesthesia awareness.

4Altered Or Distorted Sense Of Time Plays A Significant Role

Dr. Eben Alexander, a neurosurgeon, wrote a book detailing his personal experience with near-death, which happened while he was comatose due to a bout with meningitis. According to Alexander’s own account, the near-death experience was several days in length and must have occurred while his cerebral cortex was shut down due to the coma, a fact that is paradoxical since many of the sensory details he experienced are typically rooted in the cerebral cortex. This led to his assertion that there was no material cause for his experience at all.

While the personal account of a neurosurgeon’s near-death experience led to many sensational headlines (Newsweek’s cover read “Heaven Is Real: A Doctor’s Experience of the Afterlife”), Dr. Oliver Sacks, himself a professor of neurology at NYU School of Medicine, offered a very simple explanation for Dr. Alexander’s account.

According to Sacks, “A hallucinatory journey to the bright light and beyond, a full-blown NDE, can occur in 20 or 30 seconds, even though it seems to last much longer. Subjectively, during such a crisis, the very concept of time may seem variable or meaningless. The one most plausible hypothesis in Dr. Alexander’s case, then, is that his NDE occurred not during his coma, but as he was surfacing from the coma and his cortex was returning to full function. It is curious that he does not allow this obvious and natural explanation but instead insists on a supernatural one.”

3Hallucinations And Actual Perceptions Use The Same Brain Systems

Those who have gone through a near-death experience quite frequently recall that everything seemed very real—in some cases, more real than anything they had ever experienced before. While many are resolute that what they perceived was most certainly not a simple hallucination, there is a very good reason why discerning between what is real and what is hallucinated is incredibly difficult.

According to Dr. Oliver Sacks, an individual who has had a near-death experience may believe it real simply because it seemed to be real, and with good reason: “The fundamental reason that hallucinations—whatever their cause or modality—seem so real is that they deploy the very same systems in the brain that actual perceptions do. When one hallucinates voices, the auditory pathways are activated; when one hallucinates a face, the fusiform face area, normally used to perceive and identify faces in the environment, is stimulated.”

2Near-Death Experiences May Be Caused By Epileptic Activity In The Temporal Lobes

While ecstatic seizures are quite rare and occur in just a small sample of the population affected by temporal lobe epilepsy, a spike in epileptic activity in the temporal lobe may be responsible for the visions of God or of heaven that so many see during a near-death experience. A study devised by Orrin Devinsky enabled him and other researchers to “perform clinical and video EEG monitoring in patients as they are having ecstatic-religious seizures, and thus to observe the precise coinciding of their ‘theophanies’ with seizure activity in temporal lobe foci (nearly always these are right-sided).”

Historical figures that include Fyodor Dostoevsky and Joan of Arc are believed to have been influenced by temporal lobe epilepsy, which included feelings of ecstasy and the presence of something otherworldly. It may indeed be the case that those who have had a near-death experience may have had similar epileptic activity in the temporal lobes.

Dostoevsky once said the following of his ecstatic seizures: “I would feel the most complete harmony in myself and in the whole world, and this feeling was so strong and sweet that for a few seconds of such bliss I would give 10 or more years of my life, even my whole life perhaps.” Dostoevsky’s description sounds quite similar to those made in accounts of near-death experiences, lending even more credence to the theory that epileptic activity in the temporal lobe may play a significant role.

1Neurology And Religion Are Not Necessarily Contradictory

While there have been countless studies done on near-death experiences, researchers have not necessarily disproved the totality of the experience as the simple result of normal neurological function. There is the famous case of “Maria,” an individual whose near-death experience involved veridical perception during cardiac arrest. After being resuscitated, she told a social worker that she had gone outside the hospital and seen a tennis shoe on the ledge of a window on the third floor. The social worker not only found the shoe but also recognized that there was no other way for her to have known all of the details she had relayed.

Another famous near-death experience is that of Dr. Tony Cicoria, who was struck by lightning in 1994. A few weeks after the lightning strike, Dr. Cicoria, who possesses a doctorate in neuroscience, suddenly felt overcome with a desire to learn to play and write music. He was changed by the experience, and according to his own account, “saw no contradiction between religion and neurology—if God works on a man, or in a man, He would do so via the nervous system, via parts of the brain specialized, or potentially specializable, for spiritual feeling and belief.”

J. Francis Wolfe is a freelance writer and a noted dreamer of dreams. When he’s not writing, he is most likely waiting for “just one more wave,” or quietly reading under a shady tree.

Humans do weird stuff. Sometimes, we don’t even realize our behaviors are strange until we really stop to look at ourselves objectively. Then, it’s only natural to wonder why we do that weird stuff. So in the spirit of analyzing ourselves, here are some of the odd things we do every day and the leading explanations for why we do them.

10Not Replacing The Toilet Paper Roll

On the scale of difficult things to do, replacing the toilet paper roll lands way down near the bottom of the list. Still, for some reason, many of us have a difficult time completing this simple task with any level of consistency. Why is that? The reason for our TP sloppiness, according to a pair of psychologists from the University of New York, isn’t really due to laziness but because replacing the roll isn’t the slightest bit stimulating and offers virtually no intrinsic reward (except to the anal retentive).

Similar chores like taking out the trash or doing the dishes are equally boring and unmotivating, but at least they give us the satisfaction of keeping things stink- and rodent-free. Properly loading the toilet paper might make things look a little better, but so what?

The NYU psychologists, Edward L. Deci and Richard M. Ryan, say that for humans to be truly motivated to do anything, the task must meet three psychological needs: competence, autonomy, and relatedness. The chore should be challenging enough to make us feel competent when we complete it. It should make us feel like we have some sort of control over what we’re doing. And it should give us the sense that we’re enhancing our relationships with loved ones. This theory is known as the self-determination theory. Replacing the TP falls far short of meeting those three criteria. The only one it might fulfill is relatedness—that is, if you live in a very “we’re all in this together and we all pitch in with the chores” type of household.

Thus, getting a spouse or roommate to always properly replace the toilet paper or to do any other mundane task is probably a lost cause. Unless you can psychologically convince them that doing so takes a certain level of proficiency, that they’re by no means a “slave” to forever doing the chore, and that it will make them more connected to others. Now that’s a difficult task.

9Desire To Bite Cute Things

Any time there’s a baby around, someone invariably tells the baby (in the obligatory cutesy voice) that they’re “gonna eat them up” or “bite their toes” or eat some other body part. Similar conversations happen when puppies are around, and you may have even seen someone (or caught yourself) pretend-chomping on a puppy’s paw. What’s the deal with this? Why do we have the urge to jokingly munch on cute things?

Scientists have two main theories for this phenomenon. The first idea is that somehow our pleasure-sensing wires are getting crossed in the brain. When people (women in particular) catch a whiff of a newborn baby, we get a rush of dopamine similar to what happens when eating delicious food. It’s thought that we relate cuteness to this dopamine-inducing scent, which also reminds us of food. This overlap in senses unconsciously gives us the desire to put cute things in our mouths.

The other explanation is that it’s a form of play biting, which is common in many mammals and is a behavior from our animalistic sides. Many animals nip, pseudo-bite, and wrestle in a friendly, playful manner. It’s not entirely clear whether this is done to hone fighting skills, boost motor skills, or simply for fun, but the behavior usually happens between trusted allies. It takes a lot of trust to put your hand in someone’s mouth and let them bite down. So, if for nothing else, play biting is used to increase social bonds, and that could explain why we unconsciously do it when we feel the urge to get emotionally close to something cute.

8Inappropriate Laughing

Most of us are guilty of laughing inappropriately at one time or another, such as when we see someone fall down and get hurt or when we’re relaying bad news. And although we know there’s nothing funny about Grandma’s death, we may still find ourselves trying to hold back fits of laughter at her funeral. Laughing in these types of situations isn’t necessarily okay by social standards, but it’s apparently fairly common, and there’s a good reason for it.

When we laugh in a solemn circumstance, it doesn’t mean we’re cold-hearted or disrespectful. In fact, it’s likely a sign that we’re under a great deal of emotional stress and our body is using laughter as a way to relieve some of the discomfort or tension. Similarly, chuckling when someone falls down or otherwise gets hurt is believed to be an evolutionary function letting the tribe know that, although the person might be embarrassed or slightly injured, he’s not gravely wounded, and there’s no need for alarm.

Laughing, in general, is rarely a response to something being legitimately funny. Neuroscientist Sophie Scott explains it’s used most often as a method of social bonding—to let people know that we like them, we agree with them, or we’re in the same group. Knowing that, we shouldn’t feel so horrified if our neighbor lets out a chuckle while explaining how he ran over our dog. It’s possible he simply feels really uncomfortable and is instinctively trying to connect with us during an awkward situation.

7Fascination With Psychopaths

A good size of the population has a fascination with the macabre and specifically psychopaths. Nightly entertainment is chock-full of crazy, psychotic killers, and for some reason, we can’t get enough of them. What might our insatiable interest in the vilest of humans say about us as a people? There are three main theories floating around to explain this obsession.

The first idea is that watching or hearing about psychos allows us to temporarily step out of our conscientious, law-abiding shoes and vicariously step into the shoes of someone who only thinks about himself. He doesn’t do any of the things we automatically do every day, like worrying about others’ feelings or being fair. Imagining ourselves as that person (even unconsciously) temporarily liberates us from these obligations without actually causing any harm.

In contrast, forensic psychologist J. Reid Meloy says that psychopaths are a type of predator, and hearing about them connects us with our primal existence of constantly being both the hunter and the hunted. Entertaining ourselves with the stories of human predators allows us to relate with our primal, animalistic selves without experiencing the real danger of the natural world.

Finally, psychiatrist and Harvard professor Ron Schouten says that our draw to psychopaths is similar to our attraction to horror movies or roller coasters. Sometimes we just like to be frightened, and tales of psycho killers can definitely fulfill that need. This is because being frightened sends a rush of neurotransmitters, including dopamine, which evokes feelings of pleasure. In an entertainment setting where there’s no real danger, our fear doesn’t last long. On top of the dopamine-induced pleasure, we usually leave the theater or turn off the TV feeling a sense of well-being or justice (depending on how the film or show ends). This type of satisfaction keeps us coming back for more.

6Pretending To Know Stuff

Most of us have probably been in the situation where someone casually asks, “Hey, have you heard of such and such?” And almost unthinkingly, we respond, “Yeah,” even though if we took time to genuinely think about it, we’d realize we don’t actually know what they’re talking about. Similarly, some folks habitually feign knowledge when they’re well aware they know nothing about the topic at hand. Whether we purposefully pretend to know stuff or if we just sort of do it accidentally, scientists say there’s an explanation for this behavior.

Cornell professor David Dunning has researched this psychological quirk and explains that most people fake it out of convenience or to reaffirm their identity. He says that many of us don’t have a very clear understanding of what we do or don’t know and might unconsciously fake knowledge. This is because in the instant when someone asks us if we know about something, our brains start to infer, assume, and invent explanations for things. In that moment, we may say that we know something (even if we don’t) partly because we don’t want to bog the conversation down with questions and partly because our brains think we should know something about the topic. In short, the feeling of knowing is more of a sensation than it is actually sifting through our brains’ stores of information and coming up with a conclusion.

Another, perhaps more obvious, reason people pretend to know stuff is because they like feeling like a know-it-all. But why?

Neurologist Robert A. Burton explains that our society glorifies knowledge, and to have an awareness of something is a notch on the social belt—especially if you came from know-it-all parents. Being a know-it-all can become kind of an addiction. In fact, the same area of the brain lights up and the same reward pathways shoot dopamine whether we’re rewarded with a right answer or if we’re taking drugs or gambling. Thus, pretending to be the person who knows everything can be a hard habit to break.

5Crying

Crying seems like an ordinary enough experience and something we don’t really think of as strange. Yet if we really stop to contemplate what’s happening—salt water dripping out of our eyes during emotional moments—it seems a little bizarre. What do tears, eyes, and emotions have to do with each other?

One of the prevailing theories to explain human crying is put forth by Dutch psychologist Ad Vingerhoets. He argues that crying is largely a social sign that has its evolutionary roots in distress signals. Most young animals emit some type of distress sound to alert others that they need help. It’s thought that crying started as a way for humans to signify their distress (through tears) without making a predator-alerting scream or other noise. Although human babies usually have audible cries, adults often shed tears with little noise. Evolutionarily, this could have been an advantageous response, since another member of the tribe would only need to glance at the crier to see he was in trouble. Interestingly, humans are the only species to emit emotional tears. Most other animals stop making distress calls after reaching adulthood.

Further evidence that crying may have originated as a response to danger or trouble is that it also works in conjunction with our sympathetic nervous system (or the fight or flight system). For example, in addition to shedding tears, crying speeds up the heart rate, increases sweating, and slows breathing. Emotional tears even contain a natural painkiller, leucine enkephalin, which could partially explain why we sometimes feel better after a good cry.

So, although we can nowadays cry when alone or during harmless, sappy movies, the act may have started as a method of protection.

4Twitch When Falling Asleep

As much as 70 percent of people twitch or have an involuntary jerk, or hypnagogic jerk, when falling asleep. Other than amusing awake onlookers, it seems there must be an explanation for a behavior that’s apparently so common. Unfortunately, scientists aren’t entirely sure why we have the spasms, but of course, there are some educated hypotheses.

Some scientists believe it’s nothing more than an accidental reaction that happens when our nerves misfire while transitioning from alertness to sleep. This is because our bodies don’t have a definitive on/off switch, where “on” is awake and “off” is asleep. Instead we gradually transition between the state where our reticular activating system (which governs basic physiological processes) is in full force and when the ventrolateral system (which drives sleepiness and influences sleep cycles) is in charge. We can be in the middle of the two states, such as when feeling sleepy, and there can be a bit of a struggle as we firmly position ourselves into one state or another. This back-and-forth struggle is thought to cause the misfiring, and the twitches are the last fights of wakefulness.

In contrast, others believe it’s an evolutionary response left over from our tree-dwelling days, and the jerks are a primate reflex that keeps us from getting too relaxed and falling from branches.

Other types of spasms while sleeping aren’t quite the same as a hypnagogic jerk. Dreaming of falling, for instance, and then jerking oneself awake is more of an example of dream incorporation where the brain intermixes real life and the dream state.

3Gossiping

Women usually get pegged as the biggest gossips out of the two sexes, but men are guilty of this social offense as well. At least one study says men gossip 32 percent more than women per day. No matter which sex has the biggest blabbermouths, hurtful gossip can come back to bite us, yet it seems we can’t help ourselves when it comes to dishing a little dirt.

The reason for this is that most of us have an inherent desire to bond with those immediately around us—an urge that can overpower any moral obligations we might feel to mind our own business. We want to form social connections to people in our vicinity, and gossiping not only gives us something to talk about, it immediately creates a sense of trust, since the act of gossiping signals that we’re letting the other person in our confidence. In turn, the other person shares secrets, and a rapport is established. As we all know, it also gives us a feeling of superiority, is good for a laugh, and spices up boring situations.

Curiously, gossiping about people’s successes (if there is such a thing) doesn’t have the same effect. Studies show that connecting over shared dislikes creates stronger bonds than discussing shared positives.

Although gossiping means we’re throwing someone else under the bus for the sake of an immediate relationship or gratification, it might not be an entirely bad thing. Anthropologist Robin Dunbar says that gossip partly drove the evolutionary development of our brains. He argues that language first developed out of our desire to share gossip, and it enables us to talk about those who aren’t present while indirectly teaching others how to properly relate to the group.

About 60 percent of conversations between adults are about someone who’s not present. Thus, there’s no need to be paranoid that your friends are talking about you when you’re not around, as it’s almost certainly a fact.

2Liking Sad Movies

Enough grief, misfortune, and other nonsense happens to us on a daily basis that it seems ridiculous that we would want to spend our entertainment hours subjecting ourselves to more sadness. Despite this, we still regularly find ourselves sitting down to watch a guaranteed tearjerker. While it may seem counterintuitive, one reason for this is that watching tragedies actually makes us feel happier in the short term and therefore boosts our enjoyment of the movie.

Researchers at Ohio State University found that watching sad movies causes people to think about their own close relationships, which makes them feel appreciative and satisfied with their lives. Seeing tragedies on the screen causes folks to examine their own lives and count their blessings. However, the researchers point out that this reaction is not the same as those who watch a tragic movie and think something along the lines of, “Sheesh, at least I don’t have it as bad as that guy.” Those viewers have selfish thinking, are more focused on themselves instead of others, and don’t experience any boost in happiness after watching the film.

Also, according to Dr. Paul Zak, seeing movies or hearing stories about others causes us to feel empathy and prompts our brains to release oxytocin, which increases our feelings of caring. Zak even refers to oxytocin as the “moral molecule” because of how it makes us more trustworthy, generous, and compassionate. Right after a sad movie and the ensuing rush of oxytocin, we feel more connected to the people around us and overall more satisfied—even if we are shedding some tears. This feeling keeps us coming back for even more depressing flicks.

1Thinking Silence Is Awkward

Regardless of whether there is anything of value to say, many of us feel a burning desire to fill every silent moment with some type of conversation. What’s so bad about just sitting quietly with someone, and why does prolonged silence make us feel so awkward?

Like many of our behaviors, it all comes down to our primal desire to belong and fit in with the group. According to psychologist Namkje Koudenburg, when the dance of conversation doesn’t follow the traditional ebb and flow, we start to worry that something might not be right. We may wonder if we’re uninteresting or not relevant, which makes us worry about our position in the group. On the other hand, when the dialogue is bouncing back and forth as expected, we feel socially validated.

That said, not all cultures experience awkward silence in the same ways as Americans and others. For example, in Japan, a long pause can be a sign of respect, especially when considering a serious question. Cross-culture businesspeople are even trained on this etiquette, so they don’t assume a silent Japanese colleague is unsatisfied with the negotiation or whatever else the conversation is about.

The Finnish, Australian Aboriginals, and those in many Asian countries are also known for long, silent pauses in their talk and don’t see them as a sign that the conversation has broken down. Rather, it’s not uncommon for people from these countries to think Americans talk too much and dominate conversations.

Incidentally, for those of us where nonstop talking is the norm, researchers say it only takes four seconds of silence for things to get awkward.

Content and copywriter by day and list writer by night, S. Grant enjoys exploring the bizarre, unusual, and topics that hide in plain sight. Contact S. Grant here.

We probably do not pay attention to the shapes of lots of things we see around us every day. This is even though we would probably realize something was amiss if we saw them in a different shape. Imagine if you saw a circular television or a square coin.

The shapes of most everyday items are not random as you might think. Sugar is always in cubes, televisions are rectangular, and doughnuts are round for a reason. Most of the time, the shape is selected for practical reasons. Sometimes, they also have one or two things to do with the history of the product.

10 Why Sugar Is In Cubes

Sugar used to be sold in tall, hardened cones called sugar loaves. People went through quite an ordeal to get sugar ready for tea. Users first had to break the sugar apart with hammers or mallets that had chisels. Later, someone came up with the pliers-like sugar nippers to cut the hardened sugar into lumps.^[1]

Users who preferred granulated sugar shattered the lumps with a mortar and pestle or spice mill. Some just saved themselves all the trouble and inserted the whole cone into their cup of tea. Part of it melted into the tea, and they dried the rest for future use. Lucky buyers could also purchase already-broken sugar in lumps, which was sold by weight.

The whole problem with sugar came to a head in the 1840s when Juliana Rad sliced her finger while cutting sugar. Juliana was the wife of Jakub Krystof Rad, who owned a sugar mill. She complained to Jakub, asking why he could not make sugar that would fit in a cup and save people all the trouble. This made Jakub invent the first press that made sugar into cubes.

9 Why American Football Is A Prolate Spheroid

American football is played with a prolate spheroid ball because that is the shape of a pig’s bladder. The first American footballs were made of inflated pig bladders. Later, people started covering the bladder with stitched leather pieces. The balls still have those stitches, although they are only added to improve handling during play nowadays.^[2]

The shape of the ball did not change when the pig bladders were replaced with rubber in the late 1800s because the footballs were easier to throw that way. However, the change came at a cost. The balls are hard to pick up when they fall. It is also difficult to determine where they will land after a bounce, making it a nightmare for players and game developers.

Game developers often encounter difficulties when determining how to program the movements of the ball. While a regular soccer ball will go in one direction when it bounces, an American football can go in 30 different directions. Interestingly, early soccer balls were made of pig bladders but became rounder after the invention of rubber because they were easier to kick that way.

8 Why Airplane Windows Are Rounded

Airplane windows are round (or oval) because square windows become stressed when the cabin is pressurized. The continuous pressurization and depressurization of the airplane can cause the window to explode midflight, crashing the airplane.

The first commercial jetliner was the British de Havilland Comet. It launched in the 1950s with square windows. However, that turned fatal after two airplanes broke apart midair in 1953, killing 56 people in all.

Experts determined that the constant pressurization and depressurization of the airplane caused the four corners of the square windows to weaken with every flight. This culminated in the windows breaking, causing the airplane to explode and break apart midair. Square windows were quickly replaced with curved windows, which distributed the pressure over the surface of the window.^[3]

7 Why Cartoon Villains Are Triangular

Have you ever noticed that the villains in cartoons, live action, and animated movies all look alike? They often have horns, pointed ears, protruding chins, sharp eyes, pointed wings, V-shaped eyebrows, and devilish goatees.

This is not a coincidence. It is because the facial and body shapes of villains are often drawn or designed to resemble triangles with pointed tips. Filmmakers and animators use triangles for villains because our faces look triangular when we are angry. People also notice triangular and angry faces faster because they appear threatening.^[4]

For movie directors, threatening and angry means evil. This is something backed by science. In one study, volunteers noticed the mad expressions first when shown the faces of smiling, angry, and neutral people. They also noticed the downward-facing triangles first when shown pictures of four triangles pointing up, down, left, and right.

6 Why Stop Signs Are Octagonal

Stop signs are the only octagonal (eight-sided) road signs out there. They are like that because the government wants them to be easily distinguished from other road signs even when viewed from the back.

The first stop signs appeared in 1915. At the time, they were square with a white background. “STOP” was written in a black font. The sign worked at first until more cars started to appear on the roads in the 1920s.

The American Association of State Highway Officials (AASHO) came up with a new eight-sided “STOP” sign that drivers could easily recognize, even if they did not understand or could not see whatever was written on it.

The eight-sided stop signs had yellow backgrounds with black lettering and outlines. The background only became red with white lettering in 1954. The AASHO changed to a red background because traffic lights already used red to mean “STOP.”^[5]

5 Why Televisions Were Once Round

Today’s televisions are rectangular because movies created before the invention of the television were made for projection on a rectangular screen. Interestingly, the first televisions were either circular or rectangular with round edges. Early televisions were round because they contained round cathode ray tubes (CRTs). CRTs were round because they were cheaper to make that way.^[6]

The first CRTs were not made for television but maintained their shape when televisions were invented. Rectangular CRTs came later, but they kept their round edges because it was difficult to make glass tubes with flat edges. Televisions became fully rectangular as manufacturers moved to liquid crystal displays and LED screens.

4 Why Doughnuts Have A Hole In The Center

The origin of the ring doughnut remains hotly debated despite its popularity. People have come up with all sorts of theories about how doughnuts ended up with a hole in the center. One says that a Native American man unwittingly made the first ring doughnut when he shot an arrow into the center of a pastry while aiming at a woman.

Another says that some bakers created the first ring doughnuts. Supposedly, when they added eggs to their dough, the final products were often uncooked in the center but overcooked at the edges. They created the holes to eliminate the gooey centers.^[7]

However, most sources credit a sailor named Hanson Gregory (1832–1921) as the inventor of the ring doughnut even though they do not agree on a single story. One version says that Gregory invented the ring doughnut when he forcefully put some pastries he was eating through a spoke of his ship’s wheel in 1847.

According to another theory, he created the hole to make his doughnut lighter after six of his friends fell overboard because their pastries were too heavy. A third notion says that Gregory asked his mother to make the hole so that they could use lesser amounts of ingredients to make their doughnuts.

In a 1916 interview with The Washington Post, Gregory said that he created the first ring doughnut in 1858. He explained that doughnuts were made in twisting or diamond shapes at the time. They were called fried cakes and twisters.

The insides of the twisters and fried cakes were often uncooked long after their outsides were cooked, making them difficult to digest. Supposedly, Gregory invented the ring doughnut when he made a hole in the middle of a pastry before it was fried. That way, the inside and outside cooked at the same time.

3 Why Love Is Represented With A Heart Shape

Love is universally depicted with a heart shape that does not look like a human heart. Several theories have been proposed for this, but the two most common ones involve the extinct silphium plant and the philosopher Aristotle.

You have probably never heard of the silphium plant. It was popular among the Romans and Greeks who used it as a food seasoning, cough syrup, and contraceptive. They used it for contraceptives so much that they harvested it into extinction in the first century AD.^[8]

Some historians say that the seedpod of the silphium plant looks like the heart shape we use to represent love today. As the Greeks and Romans probably used the silphium plant to represent love and sex at that time, its seedpod became the universal symbol of love.

Other historians believe that we use the heart shape for love because Aristotle and a writer named Galen described the human heart as a three-chambered structure “with a small dent in the middle.” Artists and scientists in the Middle Ages supposedly created the first heart symbol when they tried to draw the heart from the description in ancient books.

2 Why Light Bulbs Are Round

The first light bulbs were spherical. Today’s light bulbs are not spherical, but they still maintain a teardrop shape, just like their predecessors. That is, they are slimmer at their bases and wider at the center with a pointy tip.^[9]

Early light bulbs were spherical because they produced light using filaments placed at their centers. A sphere is the most practical shape that allows a bulb to evenly deliver light across a certain area. Modern LED and compact fluorescent lamp (CFL) bulbs are not spherical but maintain the teardrop shape because makers want to stay with their traditions.

1 Why Coins Are Round

The earliest coins came in different shapes ranging from rectangles to circles with holes in their middles. The year in which the first coin appeared remains disputed even though historians agree that it was sometime around the sixth and fifth centuries BC.

Greek historian Herodotus wrote that the first coins were produced in Lydia, which was in today’s western Turkey. Herodotus added that the coin was made with electrum, a naturally occurring alloy of gold and silver. One account says that the coins were oval, while another claims that they were rectangular. Whichever is true, they were clearly not circles.

The Greeks and Romans later jumped on the coin fad. However, they made their coins round to prevent fraud. Coins of the day were made of valuable metals, and it was quite common for people to chip their corners off. They called this coin clipping. It was illegal and reduced the value of the coin.^[10]

The Greeks and Romans created the round coin because it could be quickly spotted if it were ever clipped. Other accounts say that round coins also won over other shapes because they were easier to count, stack, and mint.