“Needs more salt.” Ever thought that when you tasted something? But salt doesn’t just make meat or soup taste better. It can also improve the taste of foods such as coffee, chocolate, or oatmeal. So, how does salt get this superpower?

Worth Its Salt

Salt is a chemical compound made up of two different elements: sodium and chloride. Sodium is mostly responsible for the salty taste, thanks to some special cells on your tongue. Your tongue is covered with tiny bumps called papillae. Inside those papillae are taste buds, tiny cells that inform how things taste. 

Your taste buds can detect five basic tastes: sweet, sour, salty, bitter, and umami. (Umami is a savory flavor often found in meats and other foods.) Your taste buds can detect these flavors on any part of your tongue, but certain areas of your tongue are more sensitive to certain flavors. The front and side of the tongue are the most sensitive to salt.

When your taste buds detect an increase in sodium, signals are sent to your brain that what you’re eating is salty. Just a few compounds are interpreted by your taste buds as “salty.” Typical table salt is sodium chloride, while other types of sodium register as salty and bitter, or just bitter. The added bitterness is why salt substitutes often don’t measure up to the real thing.

This is simple science — basic chemistry and biology working together. As for why many people often react favorably to that salty sensation, however, that isn’t as certain. One theory is that in addition to salt affecting specific taste receptors on our tongue, the presence of salt in a meal also creates a more pleasurable mouthfeel.

It’s also possible that salt improves the taste of food by blocking the receptors on your tongue that register bitterness. (Bitterness is often seen as a negative trait in food, possibly because we’ve evolved to avoid the taste of harmful and poisonous plants). 

This allows salt to improve the flavor of foods that are naturally bitter, such as black coffee. By dialing down bitterness, salt also helps make other foods, such as dark chocolate, seem sweeter.

Salt also attracts H2O molecules, which is why it helps absorb moisture and water (as anyone who likes to dry rub a steak or grill an eggplant can tell you). By decreasing the amount of “unbound water” (water not bonded to other components) in food, flavors concentrate and can taste stronger. Absorbing water also makes it easier for these flavor components to escape into the air, creating a nice aroma that can make food seem to taste more flavorful. 

But salt improves food only to a point (called the “bliss point”). After that, too much salt in food can make it unpalatable. That’s why a glass of seawater isn’t as tasty as water from the tap. However, people have different bliss points — some prefer more salt in their food than others. 

Studies have shown that, over time, people can learn to like food with less sodium, even though they find it bland at first. That’s good, because a diet with too much sodium can raise your blood pressure and cause other health problems. 

So the next time you find yourself asking if something needs more salt, consider whether or not you’d just like more salt.

Chances are, at one time or another, you’ve had the feeling that someone is staring at you, as though another person’s gaze is a tangible beam. You may even look and find that to be the case. Or perhaps you’re the one doing the staring, and avoid doing it for too long for fear the object of your attention will whip around and catch you.

This phenomenon is known as scopaesthesia, or the psychic staring effect, defined as the ability to tell when someone is looking at us. But is it real?

Sixth Sense or Nixed Sense?

That question of how this “sixth sense” works, or if we even have one at all, remains a subject of dispute between parapsychologists (who study psychic phenomena such as telekinesis and clairvoyance) and skeptics. There are studies on the topic dating back to the late 19th century, but none have been accepted by mainstream science.

In 1898, psychologist Edward B. Titchener wrote that his students described the sensation as a stiffness at the base of their neck, “sometimes accompanied by a tingling.” He never fully detailed the experiments he ran at Cornell University, but wrote that he found no evidence of psychic abilities. He posited that people turning to see if someone’s staring is what attracts the other person’s attention in the first place, creating the illusion that they’d been caught looking. 

Later studies found that the accuracy of subjects who could identify when they were being looked at was no better than chance, while other studies reported small but statistically significant accuracy. In 1993, researchers suggested in the Journal of Parapsychology that experiments shouldn’t ask subjects to guess if they’re being watched, but should instead monitor an involuntary physical response, such as electrodermal activity (changes in the skin’s ability to conduct electricity).

Studying the staring effect this way has led to mixed results. Researchers from the University of Freiburg and University of Northampton found that subjects showed significantly higher skin activity when they were stared at, despite not knowing when this was occurring during the experiment. 

Other researchers have concluded that studies concerning the staring effect are influenced by experimenter bias. One study published in the Journal of Parapsychology found that proponents of parapsychology unconsciously influence subjects’ responses through subtle cues and interactions, whereas skeptics conducting the same tests with the same subjects yielded different results.

Yet if scopaesthesia isn’t real, what explains this sensation that so many people claim to have experienced?

Looking for Cues

For starters, it’s possible we only remember when we’ve turned around and someone was staring at us (versus when we’ve turned around and nothing was there), reinforcing the belief we have the ability to tell. Professor Colin Clifford at the University of Sydney has another theory, published in Current Biology: that we think people are staring even when they’re not. 

His team’s study concluded that human brains are wired to believe we’re being watched, even (and especially) when we lack the data to confirm it — for instance, when it’s dark or someone’s wearing sunglasses.

This would make sense, evolutionarily speaking. By being able to sense subtle cues — such as someone in our peripheral vision, a reflection, or a change in the direction of sound they’re making — we can better protect ourselves from attack. This may not be particularly useful when you’re riding an elevator, but it would be very helpful to early humans traversing dark jungles filled with predators. 

Over time, evolution may have wired our brains to “look without looking” — a defensive mechanism that in our modern society can misinterpret external cues and make us a bit paranoid that danger lurks just out of view.

Then again, we may have evolved it for a very different reason: to communicate and understand one another better. By having a honed sense of where someone else was looking and picking up on other subtle signals, early humans could better coordinate hunting and defense, as well as teach skills and share other social cues. 

The fact that human eyes have more contrast between the white sclera and black pupils may even make it easier for us to notice slight changes in visual attention, even in the far periphery. This skill may be why you can sense someone barely in your line of sight turning their gaze toward you.

Then again, they might not be looking at you at all. Maybe the staring effect is just us wanting to feel like the main character sometimes.

Whether they’re writing their grocery lists or using a pair of scissors, about 90% of folks favor their right hand. Across cultures, continents, and historical eras, lefties have always been in the minority.

But despite decades of research, scientists still haven’t found a specific reason why roughly one in 10 people are naturally left-handed. Instead, evidence suggests handedness — or your preference to use one hand over the other — is shaped by multiple factors.

Genetics plays a role, but it’s not as simple as being born with a single, specific “southpaw gene” — it doesn’t exist. So let’s get right (or left) to business and dig into what gives you your handedness.

Is Left-Handedness Genetic?

Somewhat confusingly, the left and right hemispheres of your brain control your motor skills on the opposite sides of your body, meaning the right side of your brain is responsible for your left arm and hand. But because they rarely control behaviors equally, you typically prefer one hand over the other. This is called cerebral lateralization.

For right-handed folks, motor control over their hand is better developed in the left side of the brain, while the opposite is true for lefties. Language, on the other hand, is dominated by the left hemisphere for most people, regardless of how they write. 

That means, in the brains of most right-handed people, hand control (writing) and language are more closely connected, neurologically speaking. This could explain why most humans prefer to write with their right hands.

You could even have a preference for your left hand before you’re born. Studies have shown fetuses will suck one thumb more than the other as early as 15 weeks.

Research shows that your genes play a big role in whether you’ll be right- or left-handed. We’ve known for decades that left-handedness tends to run in families: Studies show that when both of your parents are left-handed, you’re much more likely to be, too. 

If your parents are right-handed, meanwhile, you’re very unlikely to be left-handed. This suggests that handedness could be passed on from parents to their children, but no “left-handed gene” has been discovered. Instead, like many human traits, it’s believed to be a combination of dozens of different genes, as well as which ones are turned “on” or “off.” 

Plus, if handedness was purely genetic, then identical twins — who usually share 100% of their DNA — would always be both right-handed or left-handed. However, that’s not the case, as one twin may be a lefty and the other a righty. 

That said, a recent meta-analysis of twin studies found that identical twins are more likely to use the same hand compared to fraternal twins (who share just 50% of their DNA). This suggests genetics still plays a significant role in the development of handedness.

Nature vs. Nurture

While genetics plays a role, so does epigenetics — which is the way your environment and habits can physically alter the way your genes work. That’s why genetically identical twins can look pretty different as they age, as different genes are turned on and off based on external factors. 

Epigenetics may also play a role in handedness, especially since lefties live in a world dominated by righties and often have no choice but to use tools and equipment designed for right-handedness — everything from scissors and gear shifts to musical instruments and sports equipment.

But given a plethora of left-handed products are more easily available to purchase these days, shopping opti, this is less likely to be a factor in modern developed societies.

Using your right hand out of convenience is one thing, but many lefties have been forced to do it. In many cultures, left-handedness was a social stigma, and children who showed signs of being left-handed were often made to write with their right hand instead. Many righties are actually lefties in disguise. At least two U.S. presidents — Ronald Reagan and Harry Truman — were lefties forced to write with their right hand. 

Studies show that as the rate of “enforced right-handedness,” which varies between cultures, has declined in recent decades, left-handedness in those populations has increased. 

Still, a “southpaw revolution” is unlikely to occur anytime soon, as natural left-handedness remains relatively rare. So you can safely assume that the pair of scissors you’re buying off the shelf is designed to be used with your right hand.