Imagine you’re meeting up with a friend, and she arrives with coffee for you both: a Starbucks coffee in one hand and a Dunkin’ coffee in the other. She hands you the Starbucks cup and sips from her Dunkin’, telling you, “I got you Starbucks because I know it’s your favorite.”

She knows you so well! You prefer Starbucks coffee, while your friend prefers Dunkin’. You are happily sipping your coffee when she suggests you try hers. You take a sip, and as you expected, it’s not as good as your Starbucks drink. But here’s the catch—your friend had actually ordered two coffees from Dunkin’ but poured yours into a Starbucks cup. She knew your bias towards the coffee brand and had a gut feeling that your preference was superficial.

In this example, your taste has been impacted by a perceptual set. Your past experiences, expectations, and beliefs have led you to perceive the coffee in the Starbucks cup as better than the Dunkin’ coffee, even though they are the exact same. Perceptual sets are a predisposition to perceive things in a certain way and focus on aspects that confirm our existing ideas.¹ Because you’ve always claimed Starbucks was the best, your brain was inclined to confirm that as you sipped it. You’re no longer going to be able to argue with your friend that Starbucks beats Dunkin’!

It may seem strange that what we see, hear, or taste can be influenced by a perceptual set, as we tend to think of our brains as objective evaluators of external stimuli. However, because we encounter an overwhelming abundance of environmental stimuli on a daily basis, perceptual sets help our brains make sense of the information. Our expectations for understanding and classifying stimuli prime the brain to perceive them in a particular way.² We are creatures of habit, after all!

Top-Down Processing: A cognitive process that uses preexisting knowledge to make sense of new information. Instead of perceiving the world objectively based on our senses, we use schemas to understand the environment to allow us to make quick decisions. Perceptual sets use top-down processing.⁴

Schema: A cognitive framework or concept that helps us to interpret and classify information. Schemas shape our expectations and guide our perceptual sets.¹

Priming: A psychological effect where exposure to certain stimuli subconsciously influences our perception of subsequent information. For example, if someone is looking for shapes in clouds after previously looking at pictures of animals, this perceptual set is activated and will make them more likely to interpret animal-like shapes. 

Selective Attention: Our tendency to focus on particular aspects of external stimuli while ignoring others, based on our beliefs and prior experiences.⁵ When perceptual sets are activated, we tend to selectively pay attention to information that aligns with them. 

Confirmation Bias: Our tendency to focus on and give greater weight to evidence that aligns with our preexisting beliefs. It’s a mental shortcut that we take to make it easier to evaluate information, but it can lead to a narrow-minded view of the world.

Psychological Sets: A group of expectations, influenced by past experiences, cultural norms, and preferences, that influence how we approach a problem or respond to information. Perceptual sets are a type of psychological set that describes how what we see, hear, taste, or feel is shaped by expectations.⁵ 

Since the 4th century BC, philosophers have debated the nature of human perception, striving to explain how we make sense of the world around us. Aristotle believed that perception was the process through which our organs (such as our eyes or nose) create sensory impressions with little influence from our mind, meaning that these impressions accurately reflect the external world. He suggested that if we perceive a pomegranate as red, it is because the fruit holds the quality of red—not because any of our previous experiences make it appear red to us. 

In the 16th century, French philosopher René Descartes argued against Aristotle’s view of perception and introduced the idea that our senses may be unreliable.⁶ He still believed that perception was driven by sensory inputs but proposed that they may not accurately reflect the material world. It was German philosopher Immanuel Kant who first suggested our brains might play a role in perception. In Critique of Pure Reason, he states: “Imagination is a necessary ingredient of perception itself,” suggesting that we passively receive sensory information, but our brains are actively involved in interpreting and organizing it.⁷ 

While perception was initially discussed philosophically to understand its role in knowledge, in the 19th century, German physicist Hermann von Helmholtz took a more scientific approach, arguing that perceptions were formed both through physiology (our senses) and psychology (our brain). Helmholtz introduced the concept of “unconscious inference,” suggesting that representations of the material world are shaped by previous experience.⁸ 

In the 20th century, Gestalt psychology was founded, a school of thought that emphasized that the whole of something is greater than the sum of its parts. This laid the foundation for the idea of perceptual sets, as it suggested our brains categorize information in groups or sets.⁹ 

In 1955, American psychologist Gordon Allport coined the term perceptual set, defining it as “a perceptual bias or predisposition or readiness to perceive particular features of a stimulus.” Essentially, Allport argued that our brain is primed for selective attention based on schemas.¹⁰ 

In the same year, psychologists Jerome Bruner and Leigh Minturn tested Allport's theory on perceptual sets. They wanted to know if what someone expects to see (based on priming) influences what they perceive. In their study, participants were shown an ambiguous image that could be perceived as the letter B or the number 13.¹¹ 

One group was shown the image alongside other letters, while the second group was shown the image beside other numbers. Participants in the first group were far more likely to perceive the image as a B, while participants in the second group tended to perceive it as a 13, showing that one’s expectations, or perceptual set, influence their perception.¹¹ 

Today, there continues to be strong interest in understanding perceptual sets and how they influence our interactions with other people and our environment. Researchers explore how perceptual sets influence everything from eyewitness testimony—where expectations can shape memory recall—to consumer behavior, where branding affects how products are perceived. Companies must understand how perceptual sets will impact our interaction with products and technology in order to design user-friendly products that enhance the consumer experience and create loyal customers—just like in the case of the Starbucks coffee!

Hermann von Helmholtz

A German scientist and philosopher who took an interdisciplinary approach to evaluating his theories, combining his expertise in physics, physiology, and psychology. Early in his career, Helmholtz suggested that perception is derived from both our senses and our mind. He believed that our brains use unconscious inferences—mental adjustments based on previous experience—to interpret sensory information.¹² Helmholtz is perhaps best known for his contribution to the law of conservation of energy in physics, which states that energy cannot be created or destroyed, only converted from one form to another.¹³ 

Gordon Allport 

An American psychologist who coined the term perceptual set to describe the human tendency to perceive things based on previous experiences and expectations. Allport is best known for his theory that one’s personality impacts their perception of the world around them. Allport’s theory of personality proposed that it was made up of three different categories of traits: cardinal traits that dominate personality, central traits that are commonly shared, and secondary traits that are present only in certain circumstances. Allport had a Gestalt-like conception of personality, believing that the traits within these three categories combined to form our overall personality.¹⁴

Jerome Bruner

An American psychologist who conducted a series of experiments in collaboration with Leigh Minturn that showed that priming expectations can influence what people perceive. Bruner spent much of his career teaching at Harvard and is well known for his work in education, advocating that children have an innate curiosity and can be taught any subject at any stage in their development if it is presented to them in the appropriate manner. Bruner also believed that one’s values influenced their perception.¹⁵ 

Leigh Minturn

An American social psychologist who conducted a seminal study in collaboration with Jerome Bruner that demonstrated how context and expectations influence perception. Minturn taught psychology at the University of Colorado and has written several books. Her most famous book, Sita’s Daughters, was based on her work in social psychology and fieldwork in India and outlined the shifting cultural practices of Rajput caste women in Khalapur between 1955 and 1975 as a response to the Indian independence movement.¹⁶ 

Perceptual sets shape how we process and respond to information, influencing everything from daily decisions to how we navigate complex environments. They can help us manage cognitive load and make reasonably accurate judgments in uncertain situations.

Limiting Cognitive Overload

Perceptual sets influence how we interpret and perceive new information. While they do represent a cognitive bias, they can also be a useful tool for efficiently processing new information. Perceptual sets, and the expectations that come with them, help us categorize new stimuli and decide how to respond, reducing the mental effort required to analyze every situation from scratch. We do not have the cognitive ability to constantly process all information from our surroundings, so perceptual sets allow us to make choices that are satisfactory considering the information we are realistically able to take in. This allows us to operate according to bounded rationality when in complex environments.

To avoid information overload, perceptual sets clue us into what we should pay attention to. For example, imagine that you are at the airport for your flight. Your “travel” perceptual set will be activated, helping you focus on finding the information you need and drowning out the distractions (like the din of people talking and the allure of colorful duty-free shops). Your perceptual set will help you quickly spot relevant details, such as finding your gate number and boarding time on the screen or listening for relevant flight announcements, without being overwhelmed by every stimulus you encounter. Without perceptual sets, you would have to consciously analyze every piece of information around you, making even simple tasks—like navigating an airport—mentally exhausting.

Fairly Accurate Conclusions

Perceptual sets allow us to predict how new information will impact us. Since our perceptual sets are made up of tons of different data points—based on our previous experience, our motivations, and our culture—they usually lead to fairly accurate conclusions that allow us to navigate new experiences with greater ease.¹ Additionally, although perceptual sets are based on past experiences, they can be altered based on new information when your expectations don’t align with reality. Returning to our coffee example, now that you know you enjoy Dunkin’ coffee, you may alter your perceptual set associated with it and buy it again in the future. 

To give another example, imagine that you are a woman living in a busy city. Even if you haven’t experienced a dangerous situation yourself, you’re likely aware of the dangers of walking home alone at night. Your perceptual set will make you more sensitive to your environment. If you notice someone following you at night or hear a strange noise, you may be able to quickly perceive danger and prepare for a potential threat.

Product Interaction in Everyday Life

Perceptual sets play a major role in consumer decision-making. Our prior experiences with a brand or company influence how we perceive its products. Perceptual sets can impact how we feel about a brand, and our emotions have a big impact on the decisions we make. That’s why companies place their logo on virtually all products—you come to associate the logo with luxury, quality, or trustworthiness. 

Sometimes, brands actually focus on deviating from perceptual sets for a shock factor. For example, Nestle created an ad that transformed a bench into a Kit Kat. People would not expect the association between a bench and a chocolate bar, making the advertisement more memorable.¹⁷

Perceptual sets shape how we interpret the world, but they are not always beneficial. While they help us process information quickly, they can also reinforce biases, limit our perspectives, and stifle creativity.

Reinforcing Bias

Perceptual sets often cause us to interpret new information as validation of our preexisting beliefs, known as the confirmation bias. Unfortunately, many people have unconscious biases towards particular races, genders, and cultures, and our perceptual sets serve to reinforce these. 

One environment where perceptual sets can reinforce bias is in the workplace. You may be looking for a new coordinator to join your finance department and have over a hundred resumes to review. Since there’s a lot of content to go through, you might rely on perceptual sets to make judgments on who to interview. You may unconsciously associate certain names, genders, or educational backgrounds with skill and suitability.¹⁸ For example, you might favor male applicants due to stereotypes that suggest this demographic is better with numbers.

Limited Worldview

As perceptual sets are influenced by our past experiences and motivations, they can lead us to have a limited worldview, which makes it difficult to understand other people’s points of view. Perceptual sets cause us to ignore information that is not congruent with our expectations, reinforcing our existing ideas and potentially contributing to polarization.

Let us consider how perceptual sets influence our political decisions. Imagine you identify as a Democrat and, in the past, have voted accordingly. Your perceptual set may cause you to selectively seek and process information that confirms that your political stance is the “right” one and ignore anything that suggests otherwise. You may perceive the Democratic candidate as more favorable based on your expectations rather than the suitability of the candidate or the policies they are in favor of. It will also cause you to be close-minded to other candidates and not take the time to evaluate all the information available to you when making your decision to vote.¹⁹ 

Diminishes Creativity

Perceptual sets can contribute to functional fixedness, where we can only perceive objects for their normal or expected use, which can prevent us from coming up with creative ways to address a problem.²⁰ 

We can see how perceptual sets diminish creativity in a famous study called “The Candle Problem,” conducted by psychologist Karl Duncker in 1945. In the study, participants were given a candle, a box of thumbtacks, and a box of matches. They were asked to fix the candle to the wall in a way that would prevent it from dripping wax onto the table when lit. Duncker observed participants only using the tacks to try and fix the candle to the wall, which did not prevent dripping wax. Participants did not consider that the box in which the thumbtacks came could be used as a candle holder because their perceptual set was telling them it was simply a container.²¹ 

Duncker found that participants who were given an empty box were twice as likely to come up with a solution. In this case, participants no longer perceived the box as only a container and instead as part of their toolkit to find a solution.²¹

The Wallpaper Effect

A 2013 study set out to discover how perceptual sets impact our interpretation of social interactions. Previous studies had shown that contact between different demographic groups can reduce prejudice—a finding predicted by the contact hypothesis that was popularized by Gordon Allport, who also coined the term perceptual set. However, the effect was more prominent for people who are part of majority groups than those who are part of minority groups. The researchers wanted to determine why the delta existed.²²

The study was conducted in New Zealand, where both Maori (minority group) and European (majority group) ethnicities live. Through a questionnaire, the researchers assessed how much time people spent with friends from other ethnic groups and how they felt toward both social groups. They used census data to determine the ethnic makeup of the neighborhoods participants lived in. 

The researchers found that European New Zealanders, who were part of the majority group and living in a majority-dominated area, perceived interactions with the majority group as neutral or non-socially significant and, therefore, did not influence their perceptual set. However, their interactions with minority group members were more rare, causing them to be more significant and memorable. Additionally, it usually made their attitudes more positive as it shifted their perceptual set and made them more open and warm to minority group members. For Maori people living in neighborhoods dominated by European New Zealanders, their contact with majority group members was seen as less significant, holding less space in their mind and having less impact on preexisting prejudice.²² 

The researchers concluded that the difference between how contact affected minority group members, and majority group members was due to the wallpaper effect—when something is ever-present, it fades into the background and does not register as meaningful. Perceptual sets influence this effect, shaping how we filter and interpret our social world, making contact more impactful in some contexts than others.²¹

McDonald’s Does It Better

As we’ve seen, perceptual sets can influence how we perceive the taste of food. Brands try to use this to their advantage in the hopes that your perceptual set of their brand will be positive and, therefore, make you enjoy the food more. 
Researchers at Stanford University wanted to see how branding, especially with a company as popular as McDonald’s, influenced children’s food preferences. Sixty-three children from the ages of 3 to 5 participated in the study, where they were given food items either in a McDonald’s branded container or in plain white paper bags. The catch? All of the food was from McDonalds. They found that 77% of the children thought that the fries in the branded bag tasted better.²³ 

They also found that the perceptual set can work for foods not made at McDonalds. Fifty-four percent of children preferred carrots that were in a branded container compared to carrots that were served on unbranded paper. This showed that children have a strong perceptual set for McDonald's food, which causes them to perceive the taste of branded food as better. The study can provide insight into a useful trick for parents to get their kids to eat (and enjoy!) their vegetables—just plop them in a McDonald’s brown bag!²³

Blue Cars, Robots, and How Your Brain Chooses to See

Perceptual sets show us that our perception is influenced by preexisting beliefs and experiences because of top-down processing. When we expect something, we notice things that confirm our expectations. But there’s another kind of cognitive process—bottom-up attention—that causes us to notice things that stand out. In this article, our writer, Preeti Kotamarthi, explores how our attention is influenced by both top-down and bottom-up mechanisms and how these insights can inform designs to ensure that they capture our attention. 

Learning Within Limits: How Curated Content Affects Education

You may have seen or heard a trigger warning—a statement that alerts people that the following material may include distressing information. While they can be important in some cases, they can also cause someone to expect distress and, therefore, interpret the following material accordingly, even if it wouldn’t initially have upset them. In this article, our writer, Katharine Sephton, explores how trigger warnings in education may stand as an obstacle to learning. If people believe the class may upset them, they are less likely to stay and learn.

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