Buzz
An effect refers to a noticeable occurrence where one event triggers another, often with the cause remaining unclear. Famous examples include the Greenhouse Effect and the Placebo Effect, but scientists, psychologists, and other researchers are always curious to explore beyond the familiar. For instance, have you ever wondered why Cheerios tend to cluster together and drift toward the edges in a bowl of milk? Or why Brazil nuts always seem to rise to the top of a jar of mixed nuts? Ever noticed how your friends always seem to believe they’re right about everything? Or why does the shower curtain always stick to you? Read on to find out!
10. Cheerios Phenomenon
Think about the last time you had a bowl of Cheerios (or another cereal). Do the Cheerios keep to themselves, floating solo, or do they tend to group together? This natural behavior of small floating objects attracting each other and moving toward the edges of their container is known as the “Cheerios Effect.”
The explanation starts with surface tension, which refers to the ability of a liquid's surface to act like a kind of shield (or more accurately, a flexible membrane) that resists the penetration of floating objects. A Cheerio, being denser than milk, will stay on the milk’s surface thanks to surface tension. However, the milk level near the Cheerio will slightly dip, creating a small indentation that causes nearby Cheerios to behave the same way—essentially, they fall into the dip created by the first Cheerio. An object that is LESS dense than the liquid will naturally float, with or without surface tension’s assistance, and will move toward the edge of the container in search of the highest point.
9. Brazil Nut Phenomenon
The Brazil Nut Effect—sometimes called “granular convection” or “The Muesli Effect”—is a phenomenon where larger particles in a mixture of different-sized particles rise to the top when the mixture is shaken vertically. The term comes from the tendency of Brazil nuts (typically the largest nut in a nut mix) to rise to the top and settle on smaller nuts after the container has been shaken or moved. This seems paradoxical because one would expect the largest and heaviest nuts to sink while the smallest and lightest would float to the top.
The effect was first examined in the 1930s, and while it is generally well understood, some questions remain unanswered. Two main forces are at play: “percolation,” which allows smaller particles to drop through the gaps between larger ones, and “convection,” which causes the larger objects to move upward and toward the edges of the container when there’s no higher space to occupy. Another potential factor is “condensation,” which is related to temperature, and there is also the intriguing “reverse Brazil nut problem.” The roles of density and pressure continue to be researched.
8. False-consensus Bias
Ah, the false-consensus effect. We’ve all experienced it, and we all know people who are more prone to it than others—the cognitive bias where someone mistakenly believes that others share their views more than they actually do. Your friend who follows a strictly raw, vegan diet and assumes that everyone else will eagerly jump on board with it is a classic example of this effect.
Generally, people tend to view their own beliefs, actions, and perspectives as “normal” or correct. This tendency is likely influenced by the “availability heuristic” in psychology, which describes the process of making decisions based on what comes to mind most easily. Since we often surround ourselves with friends, family, and others who share similar opinions and values, this homogenous social environment can reinforce the false-consensus effect.
The strength of this bias seems to increase when we feel particularly confident in our views, when the topic at hand feels important, and when the social context surrounding the “consensus” is emphasized in some way.
7. Hot Chocolate Phenomenon
Fill a mug with milk or water, then tap the side (or bottom) with a metal spoon—and pay attention to the pitch of the sound it produces. Next, add a packet of hot chocolate mix and tap again—the pitch will noticeably drop. As the powder dissolves, the pitch starts to rise once more. This phenomenon is known as the “Hot chocolate effect,” first explored by physicist Frank Crawford in 1982.
Also referred to as the “allassonic effect,” this occurrence is caused by the change in the speed of sound within the mug as different substances are introduced, and as these substances alter the sound's transmission. Specifically, the density of the bubbles formed when the powder hits the liquid changes, which alters the sound that travels through the mixture.
6. Lake Wobegon Bias
The Lake Wobegon effect, also referred to as “illusory superiority,” is a cognitive bias. Named after the children in Garrison Keillor’s fictional town of Lake Wobegon, who are all “above average,” this phenomenon describes the tendency for people to view themselves as better than others—in other words, above average—when it comes to various abilities, skills, performance, and intellect. A common example of this is found in drivers, who often believe they are better than others on the road. A 1981 study involving drivers in the US and Sweden revealed that 93% of Americans considered themselves above-average drivers (compared to 69% of Swedish drivers). Additionally, when asked about driving safely, 88% of Americans and 77% of Swedes rated themselves in the top 50%.
Illusory superiority appears in many areas of life. Children in school often exaggerate their relative popularity; people often perceive their romantic relationships to be better than others'; and individuals frequently believe their ability to get along with others is above average. Common traits associated with this effect include, among others, kindness, skill, luck, and investment ability.
5. Name-Letter Phenomenon
People often have a preference for the letters in their names—especially their initials—and this phenomenon is known as the “name-letter effect.” While this may seem unsurprising, given the frequent interaction we have with the letters in our names, what makes the name-letter effect intriguing is how it subconsciously influences even the most unexpected aspects of our lives. Some studies have controversially suggested that there is a notable connection between the letters in a person’s name and certain choices they make or the outcomes—good or bad—they experience.
For example, research conducted at SUNY Buffalo revealed that individuals are more inclined to live in cities or states with names similar to their own, pursue careers that phonetically resemble their names, and even find partners who fit this pattern. The name-letter effect may also have negative implications; a study by professors from UC San Diego and Yale investigated whether baseball players with names starting with the letter K (which stands for a strikeout in statistics) were more prone to striking out. The study concluded, “We found that our own-name liking sabotages success for people whose initials match negative performance labels.”
It’s worth mentioning that these studies are often considered by many to have questionable (at best) validity, and the results could very well be attributed to statistical artifacts (errors).
4. Autokinetic Illusion
In complete darkness—like when you're out in the woods at night—if you focus on a small point of light, something strange happens. After a while, that stationary light will appear to move, even though it hasn’t budged an inch. This phenomenon, known as “autokinesis,” likely occurs because, in the absence of any reference points in the dark, your mind struggles to anchor the light in space. As your eyes make tiny movements, the image of the light shifts on your retina, tricking you into perceiving the light itself as having moved.
Though harmless in many situations, the autokinetic effect can pose significant risks to pilots flying at night. One of several intriguing illusions encountered in aviation, autokinesis can distort a pilot’s perception of guiding lights, potentially making it harder to land a plane. It can also complicate flying in formation, refueling mid-air, and various other maneuvers.
Unsurprisingly, autokinesis is often used to explain numerous UFO sightings, as the moving lights might be perceived as something alien when they’re simply a visual trick of the mind.
3. Wagon-wheel phenomenon
The wagon-wheel effect is an optical illusion where the spoked wheels of a moving vehicle appear to rotate in a way that doesn’t align with the vehicle’s motion. A car's wheels might seem to spin slower than expected, freeze in place, or even rotate in the opposite direction. While the exact cause of this effect is still unclear, several theories have been proposed.
On film, the wagon-wheel effect is easier to explain, thanks to the “stroboscopic” nature of movies. Film captures a rapid succession of still images—usually 24 frames per second—which causes missing visual information that our brains try to fill in. If a car is moving quickly, a wheel might rotate nearly one full turn within a single frame, and our minds interpret this as the wheel spinning backward. The explanation becomes murkier in real life, where one theory suggests our brains process images similarly to film, while another suggests conflicting interpretations of a visually ambiguous scene lead to the illusion.
2. Sylvia Plath phenomenon
The Sylvia Plath effect refers to a theory that attempts to explain why a disproportionate number of female poets suffer from mental illnesses. It further asserts that creative writers, regardless of gender, are more prone to depression and other mental health struggles than those in other professions. The connection between creativity and mental illness has been explored for centuries—Aristotle noted that creative thinkers and writers often gravitate toward “melancholia.”
In 2001, American psychologist James C. Kaufman, known for his extensive research on creativity, introduced the term “Sylvia Plath Effect” while investigating the relationship between creativity and mental illness. Many scholars have since conducted studies to explore the causes of mental illness, its complex relationship with creativity, the stigma around depression, and many other related topics. While the link between creativity and mental health, especially a causal one, remains unclear, the research has posed more questions than answers. However, it is evident that the connection between creative writers and mental illness exists, is more prevalent among poets, and affects women more than men.
1. Shower curtain phenomenon
Imagine you’re in the shower, singing your favorite tune, and enjoying the soothing warmth of the water. The bathroom windows are closed, and there’s no air movement in the space. Then, without warning, the shower curtain clings to you, as if it has a life of its own, wrapping around you with its damp touch. Despite your best efforts to peel it off, it just keeps sticking.
So what’s happening here? This is known as the “shower curtain effect,” a phenomenon that has been researched but isn’t fully understood. Several theories exist to explain it, with some overlapping and competing against each other.
(1) Buoyancy. As the warm air from the shower rises and pushes out the cooler air, it decreases in density, creating a pressure difference that causes the curtain to move inward. The challenge with this theory is that the shower curtain effect can also occur during a cold shower.
(2) The Bernoulli effect. This theory explains the change in air pressure by suggesting that the speed of the air aligns with the velocity of the water flowing from the shower head; in simpler terms, as the water speeds up, the air pressure drops. This phenomenon is crucial in the functioning of airplane wings, allowing them to generate the necessary lift for flight.
(3) The horizontal vortex theory. Although primarily studied using computer simulations, this theory posits that the pressure imbalance results from a horizontal vortex created by the water spray.
