New research reveals how social anxiety alters visual judgments of walking strangers

Individuals with high levels of social anxiety tend to perceive both single people and groups as walking directly toward them, even when the actual movement is angled away. The research, published in Cognition and Emotion, reveals that these perceptual biases occur at both the individual and crowd levels. The results suggest that social anxiety sensitizes the brain to potential social threats by altering how basic spatial logic is applied to moving bodies.

People who experience social anxiety suffer from an intense fear of being evaluated by others. Psychological models suggest these individuals possess threat-related perceptual biases. They naturally prioritize information that might signal interpersonal danger in social situations. Past research heavily examined how anxious individuals read facial expressions, but people often rely on broader body language to infer intent from a distance.

Researchers study this phenomenon using a concept called biological motion. To isolate movement from physical appearance, scientists use simulated human figures made entirely of moving dots placed at major joints, like the knees, hips, and shoulders. Though visually sparse, this animation style allows the human brain to instantly recognize walking patterns. Observers can deduce a simulated person’s intent or emotional state just by watching the rhythmic shifting of the graphical dots.

Past studies on this topic relied on two-dimensional dot animations. Because those specific images lacked visual depth, the figures often appeared ambiguous to viewers. Observers could interpret the exact same walking animation as either approaching them or walking directly away. In these older studies, socially anxious viewers showed conflicting responses, alternating between an intense sensitivity to approaching figures and a psychological avoidance pattern where they only saw figures walking away.

Error management theory suggests that human cognition evolved to make the least costly mistake when faced with visual uncertainty. In the context of ancestral human survival, preparing for a hostile person to approach is a low-cost mental action. Failing to detect an incoming physical threat, however, could be highly dangerous and potentially fatal. To see if socially anxious minds heavily over-apply this ancient safety mechanism, scientists needed to fundamentally remove the visual ambiguity of the flat image displays used in previous behavioral literature.

A team of psychologists at the Catholic University of Korea designed a new visual experiment using three-dimensional representations. The research team, featuring psychologists Jae-Won Yang, Jisu Choi, and Jiyeon Park, added shading and spherical perspective cues to the walking dots. This ensured the animated figures always appeared to be moving forward on a realistic ground plane. Viewers had to judge the precise angle of the approach rather than guessing the absolute direction.

The researchers recruited 147 university students and assessed them using widely accepted psychological questionnaires. They divided the students into high and low social anxiety groups based on their survey scores. The team also measured baseline depressive symptoms to ensure any observed differences were linked strictly to social anxiety, as anxiety and depression frequently overlap in the general public.

During the first portion of the experiment, participants watched a brief animation of a single dot-based figure. The character walked either straight ahead toward the viewer or angled slightly away at varying increments up to 24 degrees. The animation lasted for just a quarter of a second. Participants then pressed a key to indicate whether they felt the walker was coming toward them or safely passing by.

This test allowed the researchers to establish an individualized detection limit for every person. Participants in the high social anxiety group exhibited noticeably lower spatial thresholds than those in the low anxiety group. Highly anxious individuals categorized a walker as approaching even when the figure was angled further away from a direct collision path. Their visual processing favored the assumption that a solitary individual was walking straight at them.

The experiment then transitioned to testing a phenomenon known as ensemble perception. The human visual system uses a cognitive shortcut to rapidly extract summary statistics from a group. This allows a person to quickly judge the average direction a flock of birds is flying or evaluate the general mood of a human crowd. The researchers wanted to know if the approach bias seen with isolated figures would scale up to a larger crowd of moving strangers.

Participants viewed a digital crowd of ten dot-based figures on the screen simultaneously for half a second. The researchers customized this crowd for each person based on their original spatial detection threshold. A specific ratio of walkers in the crowd moved straight ahead, while others moved at an angle slightly wider than the participant’s tested limit. Participants had to determine if the entire crowd was approaching them on average.

The high social anxiety group exhibited a measurable bias compared to the low anxiety group once again. The socially anxious participants needed fewer straight-ahead walkers in the group to judge the entire crowd as an approaching entity. Their brains naturally skewed the average movement of the broader group toward an approaching threat. Because the researchers calibrated the crowd test using each person’s specific baseline, the group-level bias represented a separate distortion in how the anxious brain averages visual information.

The survey data offered an additional layer of detail about this visual bias. The researchers assessed two distinct types of anxiety: fear of being observed by others and fear of actively interacting with others. The perceptual approach bias correlated exclusively with the fear of being observed. The researchers suspect that because the dot-based figures lacked facial features and explicit social contexts, they likely triggered an evaluative dread rather than conversational anxiety.

A perceptual bias toward approaching strangers might explain certain physical behaviors observed in people with social anxiety. Overestimating the physical proximity of an approaching person likely inflates the subjective feeling of danger. This visual distortion could drive the physical behavioral avoidance or involuntary postural swaying often seen in clinical observations. Accounting for these automatic visual judgments could eventually assist in developing new physical therapies or exposure strategies.

The study features a few methodological limitations that will require future scientific investigation. Point-light walkers are incredibly useful abstract representations, but they inevitably fall short of naturalistic, everyday visual perception. The purposefully brief exposure times also meant the animations depicted only a fraction of a normal human walking stride. In the real world, human brains rely on continuous visual feedback to adjust spatial judgments over longer periods. Future experimental studies might use fully rendered virtual reality environments or real-life actors to test these spatial biases in a highly realistic interactive setting.

The participant pool consisted entirely of university students rather than individuals with clinical psychiatric diagnoses. Replicating the experiment with clinically defined patients would help verify the real-world application of these findings. The effect sizes recorded during the tasks also indicate that additional psychological or biological variables influence how people perceive biological motion. Still, the data support the idea that social anxiety actively reshapes basic spatial judgments in ambiguous situations.

The study, “People are approaching me: biased ensemble perception of biological motion in social anxiety,” was authored by Jisu Choi, Jiyeon Park, and Jae-Won Yang.