Scientific and Psychological Effects of Perception

The psychology of any individual, whether human or animal, is a highly complex and not yet fully understood mechanism. Many living beings are unconsciously influenced by certain psychological factors, some of which even scientists cannot explain.

The Allee Effect

The Allee effect is a biological phenomenon showing that the growth rate of a population relative to its size (or an entire species in a given area) decreases if the population size drops. In other words, each female produces more offspring when the population is larger. Named after American zoologist Walter Clyde Allee, this effect completely changed the understanding of population growth.

During Allee’s time, it was believed that smaller populations should thrive because each individual would have access to more resources. In other words, populations should grow more slowly when they are larger and faster when they are smaller. However, Allee’s research proved that when population size decreases, the number of possible pairs also drops—so growth slows down. The conclusion: the more individuals in a population, the faster it grows.

The Audience Effect and the Theory of Social Facilitation

The audience effect refers to the influence an audience has on a person or group performing a task in front of others. Discovered in the 1930s, this effect consists of two opposing phenomena: many performers (especially athletes) achieve better results when watched by a large crowd, while others feel awkward in front of an audience and perform worse than they actually can.

In 1965, social psychologist Robert Zajonc found a connection between the audience effect and the so-called theory of social facilitation. Zajonc proved that whether the audience’s influence is positive or negative depends on the relative “ease” of the task. For example, if a performer believes they will win, the audience effect will push them to perform at their best. If they lack confidence, the presence of an audience can further lower their self-esteem.

The Pygmalion Effect

The Pygmalion effect is related to the audience effect and the theory of social facilitation, combining positive expectations of the performer with the highest possible results. Named after George Bernard Shaw’s play “Pygmalion” (which inspired the film “My Fair Lady”), it’s also known as the “Rosenthal effect.”

There is also an opposite phenomenon called the “Golem effect,” where low expectations lead to poor performance. The Pygmalion effect has been extensively studied in athletics, business, and especially education. In business, it is clearly seen in managers’ results, which directly depend on what they expect from their employees.

As Professor J. Livingston noted in his research: “How managers treat their subordinates largely depends on what they expect from them.” Similarly, a study of the Pygmalion effect by Robert Rosenthal and Lenore Jacobson in a classroom setting showed that students from whom teachers expect more are more likely to excel.

The Bruce Effect

When pregnant female rodents smell an unfamiliar male, they may sometimes terminate their own pregnancy. This effect, first studied by British zoologist Hilda Bruce, has been observed in some mice, voles, lemmings, gelada monkeys, and even lions. For a while, the effect was only studied in captive animals, but researcher Eila Roberts from the University of Michigan was the first to study it in the wild.

Roberts spent five years studying geladas in Ethiopia, collecting data on 110 females from 21 different groups. After analyzing fecal samples for hormones that confirm pregnancy, Roberts discovered that when a male established dominance by taking over a group, a significant number of females terminated their pregnancies. In groups without a dominant male, birth rates were much higher.

The answer lies in the tendency of dominant males to kill young geladas. They do this because females can only mate again after raising their young, and the males lack patience. The females terminate their pregnancies because they know their offspring would be killed anyway, saving the mother’s time, energy, and resources.

The Leidenfrost Effect

If you’ve ever splashed water onto a very hot pan and watched the droplets spin around wildly, you’ve witnessed the Leidenfrost effect, named after German doctor Johann Gottlob Leidenfrost in 1796. The Leidenfrost effect is a physical phenomenon that occurs when a liquid comes very close to a surface much hotter than its boiling point. Under these conditions, the liquid forms a protective layer of vapor that separates it from the hot surface and prevents rapid evaporation.

With water droplets on a hot pan, the water eventually boils and evaporates, but much more slowly than if the pan’s temperature were above the boiling point but below the Leidenfrost point. This effect allows water, under certain conditions, to “levitate” above a hot surface. For the same reason, you can briefly dip a wet finger into liquid nitrogen without harm—but it’s still dangerous and not recommended to try.

The Diorama Effect

The diorama effect, also known as “pseudo-macro” or the “diorama illusion,” describes the process where a photographer captures real-life objects at full scale in such a way that they appear as miniature models in the photo. Sometimes called the “tilt-shift effect,” it’s worth noting that tilt-shifting is a technique that always creates a “pseudo-macro” effect. This technique can be used in digital photography to make a photo look like it was taken with a special lens.

Creating such images involves several steps. Key points include:

• Taking the photo from above;
• Blurring the edges of the photo;
• Increasing color saturation.

Of course, there’s much more to it, and you can find step-by-step guides online.

The Overview Effect

Of all the psychological effects ever named and studied, the overview effect is the rarest—only 534 people have ever experienced the conditions necessary for it. When astronauts see the Earth as a whole from orbit or from the surface of the Moon, many describe an incredible sense of scale and perspective, which is called the overview effect. Coined by writer Frank White, this effect has a profound impact on people, leaving them awestruck, inspired, and emotionally moved. Seeing Earth from space changes a person’s outlook. Astronauts return home with a new vision of how we are all connected, a sense of the meaninglessness of cultural boundaries, and a desire to care for the environment.

The Pratfall Effect

Imagine you’re head over heels in love with a girl who seems talented, kind, and beautiful. Then imagine you see her walking down the sidewalk, tripping, and falling flat on her face. For many reasons, you find yourself even more attracted to her, and you feel more appealing to her as well—all because of her clumsiness.

Widely studied in sports, business, and politics, this psychological phenomenon is known as the “pratfall effect.” First discovered and named by researcher Elliot Aronson in 1966, the results of this effect can vary. Studies show that people tend to like imperfect people who make mistakes. The effect has been analyzed extensively, and it turns out, for example, that clumsy women attract men more than the reverse, but the main principle remains: a person becomes more attractive by showing their flaws.

The Sleeper Effect

The sleeper effect is a frequently studied and controversial psychological phenomenon that shows how information influences a person’s opinion. Usually, when you see an ad with a positive slogan, you form positive associations with it (and the advertised product). However, over time, these positive associations fade, and eventually, you have no associations with the ad at all. But under certain conditions—such as when the message is accompanied by a “discounting cue”—the positive association can last much longer.

A “discounting cue” usually comes in the form of an untrustworthy information source, a disclaimer, or an unusual source. When you see a negative political ad paid for by an opponent, you might initially be skeptical, but after some time, you may start to believe it. Research claims the sleeper effect is real, but difficult to achieve in practice, so to make it effective, you must strictly follow a specific set of guidelines.