Summary: Can hearing someone say a medical injection “really hurts” make the needle feel worse? A recent Dartmouth study shows the answer is yes. Researchers found that social information—what we are told about others’ experiences—can create a self-fulfilling prophecy that changes how we perceive pain and effort.
This bias does more than influence our descriptions of pain; it alters the sensory experience itself. Expectations shaped by social cues can make physically mild stimuli feel sharper and mentally demanding tasks feel harder, even when objective stimulus intensity remains low.
Key Facts
- “Ghost” data cues: Participants viewed dot plots they were told represented ratings from previous participants. The plots were actually randomized, but they reliably set expectations for high or low pain and effort.
- Consistent across three domains: The effect appeared for experiential pain (heat applied to the arm), vicarious pain (watching others in pain), and cognitive effort (mentally rotating 3D objects).
- Confirmation bias in learning: People update beliefs more readily when new evidence confirms their expectations and downweight or ignore evidence that contradicts those expectations.
- Perceptual coloring: Expectations don’t just influence judgment; they “color” raw perception so that anticipated pain or effort amplifies sensory signals and reduces signals that would disconfirm the expectation.
Source: Dartmouth College
Imagine you’re waiting for a vaccine and someone who just had one tells you it was excruciating. Could that single comment make the injection feel worse? According to research published in the Proceedings of the National Academy of Sciences, what others tell us about an experience can shape how it actually feels.
The study demonstrates that brief social cues—suggestions about how aversive an upcoming event will be—can change both expectations and subjective experience across physical pain, observed pain, and cognitive effort.
“Our results suggest that when expectations are shaped by social information, people tend to hold onto those expectations, which in turn impacts how we feel in a long-lasting way,” says Aryan Yazdanpanah, a PhD candidate in the Department of Psychological and Brain Sciences and an Innovation PhD Fellow at Dartmouth.
To test this, researchers ran controlled experiments in which participants completed three task types following the same basic sequence: first, a social cue appeared; next, participants reported their expectation; then they received the stimulus and rated their experience.
The social cues took the form of dot plots that participants were told represented ratings from 10 previous people. Unbeknownst to them, the plots were randomized and bore no relation to the actual stimulus intensity. Still, these cues reliably biased expectations and subsequent ratings.
Tasks included an experiential pain task (non-harmful heat applied to the forearm), a vicarious pain task (videos of people displaying pain expressions), and a cognitive effort task (determining whether two 3D objects were the same after mental rotation).
Across all three domains, high-aversive cues produced higher expected and reported aversiveness, even when the physical or visual stimulus intensity was low. In short, being told an experience is painful or strenuous made it feel that way.
These effects matter for real-world interpretation of others’ suffering. “If someone truly experiences severe pain but social cues suggest it’s not serious, observers may underestimate or overlook that person’s suffering,” Yazdanpanah notes. Conversely, when others frame a task—such as solving math—as very effortful, people can experience the same activity as more taxing.
Using behavioral analysis and computational modeling, the team identified two mechanisms that sustain these effects. First, a confirmation bias in learning: participants updated their beliefs more strongly when outcomes matched the social cue and learned less from outcomes that contradicted it. Second, expectations altered perception itself, amplifying signals consistent with the expectation and muting contrary evidence.
Alireza Soltani, associate professor of psychological and brain sciences at Dartmouth, explains: “People favor evidence that aligns with their beliefs and dampen or ignore evidence that does not. This confirmation bias in learning was evident across the study.”
A practical example: in back-pain recovery, a person who expects bending to cause pain may still feel pain after healing because expectation intensifies any small sensation and suppresses signals of safety. That perceptual coloring weakens the corrective feedback needed to revise the expectation, maintaining a cycle of pain avoidance.
In today’s hyperconnected world, where personal experiences are widely shared on social platforms, such cues can spread and solidify expectations at scale. “The dynamics we observed can create self-fulfilling prophecies—feedback cycles that affect many kinds of health conditions, including chronic pain and fatigue, as well as beliefs about other people,” says Tor Wager, Diana L. Taylor Distinguished Professor of Neuroscience at Dartmouth.
Wager and Soltani served as co-senior authors. Heejung Jung, Guarini ’24, contributed as a postdoctoral researcher at Stanford who worked on the study while a graduate student at Dartmouth.
Key Questions Answered:
A: Not merely imagination. Your brain uses expectations to filter incoming information. If you’re told a mental task is exhausting, your brain biases attention toward sensations that support that belief and downplays moments that feel easy. The result is a genuine change in perceived effort or pain because perception itself is being shaped by expectation.
A: Social cues can act as filters. If you’ve been told a procedure “isn’t a big deal,” that belief can reduce your sensitivity to signs of suffering when you observe them, causing you to under-recognize someone’s pain even if their expressions suggest otherwise.
A: Yes. Past painful experiences can establish an expectation that a particular movement or situation is dangerous. Because expectation magnifies tiny sensations and reduces corrective signals, the brain can maintain the belief that the movement will hurt, creating a self-reinforcing loop that is hard to break.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this social neuroscience and pain research news
Author: Amy Olson
Source: Dartmouth College
Contact: Amy Olson – Dartmouth College
Image: The image is credited to Neuroscience News
Original Research: Closed access. “Social information creates self-fulfilling prophecies in judgments of pain, vicarious pain, and cognitive effort” by Aryan Yazdanpanah, Heejung Jung, Alireza Soltani, and Tor D. Wager. PNAS
DOI: 10.1073/pnas.2513856123
Abstract
Social information creates self-fulfilling prophecies in judgments of pain, vicarious pain, and cognitive effort
Expectations influence perception and can produce self-fulfilling outcomes, such as placebo-like effects that persist or intensify over time. Whether unreinforced social cues—suggestions about future experiences not paired with reward or punishment—can create and sustain such effects was previously unclear.
The study tested 111 participants across three stimulus domains: somatic pain (heat), vicarious pain (videos of others in pain), and cognitive effort (a mental-rotation task), each delivered at three intensity levels. Before each trial, participants saw a social cue purportedly summarizing ratings from 10 prior participants; the cues were actually randomized to represent high or low aversiveness independently of real stimulus intensity.
Across tasks, participants’ expectations and experience ratings shifted with the cues: high-aversive cues produced higher perceived aversiveness. Computational modeling and behavioral analysis revealed asymmetric learning rates: participants showed lower learning from prediction errors that disagreed with the cue and higher learning from errors that agreed with it. This confirmation bias in learning, together with expectation-driven changes in perception, explains how social cues can produce and sustain self-fulfilling prophecies.