Is seeing believing? How we make sense of the world around us

Despite the adage “seeing is believing,” what you see isn’t always what you get. Consider the viral dress photo of 2015 that split viewers into two camps: one who said the dress was white and gold and one who said it was black and blue. More than just a fun optical illusion, the phenomenon highlighted how multiple people can look at the same image or event and walk away with strikingly different interpretations. Such differences in perception can take on far greater weight when the stakes are high. To some viewers, police body camera footage can show blatant use of excessive force, while others watch the same clip and see an officer acting responsibly. Whose reality is the “real” one?

The human visual system is riddled with shortcomings. Our foveal vision—the area directly in front of us that we see with the greatest clarity and precision—makes up just a few degrees of our visual field. Everything outside that area, our peripheral vision, enters our eyes and brains in a somewhat degraded form. “All of that stuff we don’t see is the unknown unknowns, things we aren’t even aware we’re missing,” said Emily Balcetis, PhD, a social psychologist at New York University.

Our other senses are subject to the same limitations. Where one fan hears Elton John sing about a tiny dancer, another one hums along to “hold me closer, Tony Danza.” We all make sense of the world in our own unique ways.

“How we perceive and respond to any given situation is a function of what is out there in the world but also of what we as individuals bring to the table. We have goals and desires, we have fears and anxieties, and we also have beliefs that are important to us,” said Yuan Chang Leong, PhD, an assistant professor of psychology at the University of Chicago. “From the early stages of what we choose to look at to how we interpret it, bias can creep in at every stage.”

From the moment a newborn opens their eyes and hears their mother’s voice, sensory input is foundational to the human experience. As the science of perception evolves, researchers are learning more about how we make sense of the world around us and why two people’s perceptions can differ so dramatically. Those questions matter for us as individuals and for our shared reality as members of a society. “Polarization is pulling at the threads that keep us together. If we can’t even be on the same page about whether we see the problems, we’ll be really slow at trying to solve them,” Balcetis said.

Perception is typically considered a foundational function, a lower-level process than cognition. Yet in some ways, perception is more sophisticated than it’s often given credit for, said Brian Scholl, PhD, a professor of psychology at Yale University. “There’s a sense that you can just open your eyes and recognize what you’re looking at. But that is the result of tremendous computational processing in your mind,” he said.

In a dynamic scene, your eyes and brain are processing information about color, shape, motion, and orientation. At the same time, your brain is combining those features with your expectations about the world. Some of Scholl’s research, for example, has explored intuitive physics—how we can sense, at a glance, if a block tower is about to tumble or a scrap of fabric is likely to flutter in the wind or fall stiffly to the ground (Journal of Vision, Vol. 16, No. 12, 2016opens in new window; Psychological Science, Vol. 34, No. 1, 2023opens in new window). “You pack a lot more into seeing something than is typically thought,” he added.

And vision, of course, is only one piece of that complex puzzle. In recent years, sensory scientists have gotten better at understanding how our senses work in concert, said Ladan Shams, PhD, a professor of psychology, bioengineering, and neuroscience at the University of California, Los Angeles. For a long time, people operated under the assumption that each sense functioned in isolation, she said, when they actually interact with one another in intricate ways. In a forthcoming paper, Shams and colleagues suggest that multisensory information is integrated even before it is encoded in memory (PsyArXiv, 2025opens in new window). “Interaction between the senses is the rule rather than the exception,” she said.

Such interactions are constantly in flux. You may rely most on what you see when the visual input is very reliable. But if you’re driving on a foggy day, you may rely more on the sound of approaching cars than the glow of their headlights without ever realizing you’ve made the shift. Those interactions within our perceptual system can affect the way we perceive the world, from person to person and from day to day.

With so much information to process and parse, the sensory system is also subject to errors. “I tell my undergrads that everyone should take a course on perception because then we can all appreciate the shortcomings and the vulnerabilities in the way our perceptual system works,” Shams said. “It’s the best we have, but it’s just one source of information, and we should be aware that it is not always reflecting reality.”

One limiting factor is the information we individually tune in to. Our motivations and desires can exert powerful influence over what sensory information we focus on, often without our conscious awareness. Leong and his colleagues demonstrated this in a series of studies. They collected neuroimaging data while showing participants images created by morphing together faces and scenes in varying proportions—chosen because faces and scenes elicit distinct patterns of brain activity. The researchers motivated participants to want to see one versus the other by telling them they could win money if the image was more face or more scene.

When the images were ambiguous—roughly half scene and half face—people were motivated to see whichever subject would win them the prize. But they weren’t just claiming they saw it to pocket the cash. Their motivation to see faces (to win money) led those participants’ brains to actually exhibit more activity in face-processing areas and less activity in areas tasked with processing scenes. When motivated to see scenes, the reverse was true (Trends in Cognitive Sciencesopens in new window, Vol. 30, No. 1, 2026opens in new window). This is similar to unconscious bias in that both involve expectations shaping what we perceive. But whereas unconscious bias is driven by prior learned associations, this effect reflects how our moment-to-moment motivations can influence us to see what we want to see.

“When you want to see something, the part of your brain associated with that thing becomes more active,” Leong explained. “Your brain has the opportunity to bias itself to see one thing versus another, and one way it might do this is to direct your attention to the aspects of the world that favor the interpretation you desire.”

Balcetis has shown how this difference in attention can play out in real-life scenarios. In a classic example, she and her colleagues showed participants a video of an altercation between a police officer and a civilian, asking the viewers to make judgments about whether the officer used excessive force. Unsurprisingly, people who identified with the officer and described themselves as more pro-police were less likely to say the officer did anything wrong. “But what’s interesting is that this intuitive effect is contingent upon where they’re looking,” Balcetis said.

To understand how participants viewed the interaction, the researchers covertly mapped their gazes with eye-tracking technology. The more a participant identified with the officer, the more time they tended to spend looking at the officer. And the more that they looked at the officer, the more their preexisting beliefs about him influenced their judgments (Journal of Experimental Psychology: General, Vol. 143, No. 6, 2014). Viewers who did not align with the police, by contrast, were more likely to look at the civilian. By essentially tuning out half of the interaction, viewers on either side of the spectrum were susceptible to missing key details. “That’s part of the reason we have polarization, because I’m seeing different things than you’re seeing,” Balcetis said. “That means I understand the case facts differently than you do, which leads me to feel justified in reaching a conclusion about who’s culpable that’s different from yours.”

When the researchers instructed participants to pay equal attention to both characters, however, viewers changed their visual orientation—and reached more similar conclusions about the officer’s culpability. The instructions didn’t alter people’s preexisting opinions of police officers, but they did lead viewers on both sides of the spectrum to meet closer to the middle in their judgments of culpability. “The polarization as a function of their prior beliefs goes away,” Balcetis said.

Unfortunately, we don’t seem to be inclined to look at an event in new ways, even when given a chance, Balcetis added. People tend to repeat their same patterns of looking when watching a video for a second or third time. “Which means we’re not doing what economists would say is the rational approach of trying to fill in gaps when we have opportunities to gain new insight,” she said. “Why? Probably because people don’t realize there are unknown unknowns. They’re not aware that their eyes are not giving them the full picture, and they don’t know that they should correct.”

Our attention can fail us in other ways, as the famous “invisible gorilla” study of inattentional blindness vividly demonstrated. The study tasked participants with counting rapid basketball passes between players on a given team. While focused on tracking passes, about half of the participants failed to notice a person in a gorilla suit walk past the players (Simons, D. J., & Chabris, C. F., Perception, Vol. 28, No. 9, 1999opens in new window). In the years since, researchers have fleshed out more details about how and why we can miss the proverbial elephant—or in this case, ape—in the room.

One somewhat surprising finding has been that the tendency to notice or not doesn’t seem to be linked to individual factors like personality or cognitive prowess, said Dan Simons, PhD, a professor of psychology at the University of Illinois who cocreated the original gorilla experiment. Simons recently coauthored a meta-analysis of individual differences in inattentional blindness (Psychonomic Bulletin & Review, Vol. 31, 2024opens in new window) and also led a large-scale study on individual differences (in press, Royal Society Open Science). “The short answer is that individual differences in personality don’t predict inattentional blindness at all, and the same seems to be largely true for cognitive abilities. You’re not more likely to notice if you’re smarter or have better working memory or better executive control,” he said.

What does seem to matter are your goals and the demands of the task itself. If the unexpected thing is similar to what you’re paying attention to, you’re more likely to notice it. You’re more apt to see the gorilla if you’re counting passes between players in black shirts versus those in the white shirts, for example. While similarity matters, familiarity might not. In one experiment, Simons and his student Yifan Ding flashed flags on the screen while participants were engaged in a computer task. Participants were no more or less likely to notice flags from their own countries versus unfamiliar flags, suggesting that familiarity with visual stimuli doesn’t generally affect one’s ability to notice them (Journal of Cognition, Vol. 7, No. 1, 2024opens in new window).

Inattentional blindness plays out in the real world, too. It’s why a driver focused on the traffic light doesn’t notice a bike in the crosswalk, but their passenger does. In some ways, Simons added, the problem isn’t what we fail to notice. “The bigger danger here is not that we don’t always see everything. It’s that we think we do,” he said. “Because we’re only aware of the things we happen to see, and we don’t actually realize how often we miss things, we tend to think that our experiences are more complete and accurate than they actually are.”

Inattentional blindness and similar lapses are often thought of as failures of attention, Simons said, but he characterizes them differently. “We have a limited ability to pay attention to everything around us. If we want to not be constantly distracted by things we don’t care about, that ability to zero in on what we want to do is remarkable and essential,” he said.

Indeed, so-called failures of perception are a feature, not a bug. Using Bayesian models, Shams and her colleagues have shown that perceptual systems are statistically optimized to process the dizzying assortment of sensory information in our environments as efficiently as possible (Neuroscience & Biobehavioral Reviews, Vol. 137, 2022opens in new window). Some glitches in the system are the price we pay for a brain that can, in a split second, process a sound, determine which direction it came from, match the sound to the object that caused it, determine where the object is moving, and decide how to react. “The brain solves [problems] in an optimal way,” Shams said, “combining expectations and your model of the world—acquired over the course of your lifetime and the course of evolution—together with input from any given moment.”

Just as a computer changes its outputs when new data are entered, the brain can also revise its interpretations of the world when new information becomes available. In other words, minds can change. Emily Finn, PhD, a cognitive neuroscientist at Dartmouth College, has studied how interpretations change with new sensory inputs. In a recent study, she used fMRI to scan participants’ brains while they listened to an audio story with a big twist in the middle. When participants listened to the recording a second time, they experienced very different patterns of brain activity, specifically during the half of the story leading up to the twist (PNAS, Vol. 123, No. 11, 2026opens in new window). “It’s the same auditory information coming through your ears, but you have a totally different framework that you bring to understanding the information,” Finn said.

In another study, she’s exploring how other people’s interpretations of sensory input can push your own understanding in one direction or another. She shows participants photos of ambiguous scenes and asks them to fill in the blanks of a story about the characters pictured. Then the researchers tell the participants about another person’s interpretation, which can be very similar to or very different from their own. Preliminary results suggest that people exposed to an alternate perspective show very different patterns of brain activation when they view the image a second time. “Pretty much the entire brain looks different when you have this alternative perspective,” Finn said.

For a long time, she added, cognitive psychology has largely focused on finding principles that are true for all minds. “I think we’re finally taking the tools we’ve developed in the experimental tradition of psychology to apply to these thorny questions about subjective experience,” she said. It can be unsettling to feel like you’re living in an alternate reality from other people. But variety lies at the heart of creativity and innovation and problem-solving, Finn said, and we’d all be better off approaching differences in interpretation with curiosity rather than assuming malicious intent. “My hope is that we’ll use these tools not to somehow homogenize how everyone is thinking,” she added, “but rather to understand why variability arises—and when it might actually be a good thing.”