Eye-tracking reveals what people actually look at when they see a spider

University of Nebraska-Lincoln

Ask someone why they are afraid of spiders, and the answer usually involves movement. They are fast. They are unpredictable. They dart across floors in directions you cannot anticipate. But when researchers at the University of Nebraska-Lincoln actually tracked where people's eyes went when shown images of spiders, the story turned out to be more complicated than speed and surprise.

A study published in Frontiers in Arachnid Science used an SR Research EyeLink 1000, an instrument that records eye position every millisecond, to map exactly how 118 undergraduates allocated their visual attention when looking at images of spiders and other arthropods. The results challenge some straightforward assumptions about what makes spiders frightening.

The avoidance that was not quite avoidance

The expected pattern showed up clearly: when participants were shown a spider alongside a non-spider arthropod, they generally looked away from the spider. That confirmed what most phobia research would predict. People with higher spider-fear scores on accompanying surveys avoided spider images more strongly.

But when the choice was between two spiders, one plain and one displaying a distinctly spider-like cue such as a web, eggs, or visible fangs, something unexpected happened. Participants spent more time looking at the spider with the additional cue. The more distinctly "spidery" the image, the more attention it captured.

Hairy spiders broke the pattern. When one spider was visibly hairy and the other was not, participants consistently directed their gaze toward the non-hairy option. Hairiness was the one cue that reliably repelled attention rather than attracting it.

Why webs might make spiders less scary

The research team, led by graduate student Emma Brase under the supervision of biologist Eileen Hebets and psychologist Mike Dodd, has several theories about the counterintuitive finding that spider-specific features drew attention.

One explanation is simple visual complexity. An image with more features, a web draped behind the spider, an egg sac beside it, is inherently more interesting to look at. The eye may be drawn not to the threat but to the information.

Another possibility connects to the movement concern. A spider in a web is a spider in a known location, doing a predictable thing. A spider on the ground, with no web, could bolt in any direction. The web may function as a signal of predictability, reducing the perceived threat enough that the viewer can engage rather than avert.

Dodd also raised the role of anthropomorphism. Certain contexts may make spiders seem more relatable. A web functions like a home. Jumping spiders, with their two large, forward-facing eyes, have a vaguely face-like appearance. These humanizing features could shift the emotional response from fear toward curiosity.

Biology meets psychology meets conservation

What makes this study unusual is its disciplinary origin. Phobia research typically lives in psychology and psychiatry departments. This project grew out of a biology lab. Hebets, a professor of biological sciences who studies spider behavior, partnered with Dodd's psychology lab specifically to bring eye-tracking methods to questions about human-spider interactions.

Hebets's interest is partly practical. Spiders play significant ecological roles in pest control, crop protection, and biodiversity maintenance. If researchers can identify what specific features trigger negative reactions in humans, conservation communication could be designed to emphasize the features people find tolerable or even appealing while avoiding the features that trigger aversion.

The work could also improve treatments for severe arachnophobia. Current therapeutic approaches, primarily exposure therapy, do not typically account for which visual features of spiders are most distressing. If hairiness is a stronger trigger than, say, body shape or leg count, therapies could be calibrated accordingly.

Limitations and next steps

The study used still photographs, not video. Given that movement is frequently cited as the most disturbing aspect of spiders, the absence of motion is a significant gap. Whether the attention patterns observed here would hold when spiders are moving remains untested.

The sample was 118 undergraduates, a relatively small and demographically narrow group. Cultural variation in spider attitudes is well documented, and the findings may not generalize to populations with different environmental relationships to spiders.

Later this year, the team plans to collect eye-tracking data at an art exhibition featuring installations made from arthropods, created by University of Wisconsin-Madison artist Jennifer Angus. That setting will test whether the same attention patterns emerge when spiders are encountered in an aesthetic rather than clinical context.