In an era when social media blurs the line between public and private speech, how do people decide whether to speak their minds or stay silent?
A new study from researchers at Arizona State University and the University of Michigan, published in the Proceedings of the National Academy of Sciences , or PNAS, offers a groundbreaking look at the strategic trade-offs individuals make when facing the threat of punishment for dissent.
The work, co-authored by Professor Stephanie Forrest and Assistant Professor Joshua J. Daymude in the School of Computing and Augmented Intelligence , part of the Ira A. Fulton Schools of Engineering at ASU, and Robert Axelrod from the University of Michigan, introduces a mathematical model to explain when people choose to express dissent or self-censor.
The findings shed new light on how surveillance, punishment and boldness interact to shape societies, especially under authoritarian conditions in which expressing one's true opinion can carry real danger.
Science behind silence
The new paper, "Strategic Analysis of Dissent and Self-Censorship," explores how individuals and governing authorities influence one another's behavior over time.
"Modern technologies — from facial recognition to algorithmic content moderation — have transformed the landscape of dissent," Daymude says. "Our goal was to move beyond intuition and provide a formal way to understand when and how self-censorship emerges."
The researchers developed a simulation in which individuals balance their desire to express dissent against the fear of punishment, while an authority dynamically adjusts its surveillance and policies to minimize both total dissent and enforcement costs.
The results reveal that self-censorship isn't simply a product of fear. It is a rational, strategic response shaped by the interplay of boldness, surveillance and punishment severity.
When fear becomes a strategy
At the heart of the study is a model describing three distinct behaviors: compliance, self-censorship and defiance. The researchers found that when punishments are uniform, such as blanket bans or internet shutdowns, self-censorship tends to dominate. When punishments are proportional, such as escalating penalties for repeated offenses, individuals may still take small risks to express dissent.
"A population's willingness to speak out early on, and suffer the negative consequences, has an outsized effect on how long it takes an authority to suppress all dissent," Forrest says. "This is because the cost of punishing an entire population simultaneously is too high."
In simulated societies, authorities that began with moderate policies often evolved toward stricter control, echoing historical cases such as Chairman Mao Zedong's "Hundred Flowers Campaign," which encouraged open critique before abruptly reversing course. The model showed that as tolerance is reduced and surveillance intensifies, dissenters self-censor progressively, leading to near-total compliance over time.
However, populations with higher "boldness," or a measure of willingness to risk punishment, resisted longer. In these cases, authorities struggled to fully suppress dissent, even when equipped with strong surveillance and severe penalties.
Crossing disciplinary lines to decode dissent
The research reflects the interdisciplinary mission of Forrest and Daymude. While both are computer science and engineering faculty members, they also play key roles in ASU's Biodesign Center for Biocomputing, Security and Society , directed by Forrest, a pioneer in evolutionary computation and complex systems. Together, the team brought computer science and mathematical rigor to one of humanity's oldest political questions: What makes people speak or stay silent?
Daymude's expertise in distributed algorithms and collective behavior complemented Forrest's decades of work applying biological principles to computing. The collaboration with Axelrod, a renowned political scientist known for his work on cooperation and conflict, extended the project's reach into the social sciences.
The fragile future of free expression
The implications go far beyond academic theory. From citizens in authoritarian regimes to users navigating content moderation on global social platforms, the pressures that shape public expression are everywhere. The study highlights how easily self-censorship can spread and how difficult it is to reverse once established.
"Self-censorship can start as a form of self-protection," Daymude says. "But when people begin to silence themselves preemptively, before any punishment occurs, it becomes a powerful tool for control."
By clarifying the strategic nature of dissent, the researchers hope their work can inform policymakers, platform designers and advocates for free expression.
"Ultimately, our findings show that preserving open dialogue depends not only on laws or technology," Forrest says, "but on the courage of individuals and the collective willingness to keep speaking, even when it's uncomfortable."
