People may think of survival as an individual act—every animal (and person) for themselves. But a new study from UCLA suggests that when it comes to facing hardship together, social groups may function more like a unified system than a collection of separate individuals.
The research, published in Nature Neuroscience, explored how mice huddle together for warmth in the cold and what that means for shaping group behavior and collective survival strategies.
Why it matters
At a time when social isolation is recognized as a serious health risk, and conditions like depression and schizophrenia are understood to involve disruptions in social connection, findings like these offer new insights into our understanding of social decision-making and group cohesion more broadly.
What the study did
Researchers tracked groups of mice moving freely during cold exposure, using behavioral and thermal imaging to study how they organized themselves for warmth. They identified four distinct ways an individual might end up in a huddle: actively choosing to join, being sought out by others, choosing to leave, or being left behind, and monitored brain activity in the prefrontal cortex, the region involved in decision-making and social behavior. They then selectively silenced that brain region in some animals within each group, leaving their groupmates untouched, to see what would happen to the collective.
What they found
The prefrontal cortex tracked not just an animal's own choices, but those made by its social partners, suggesting the brain is continuously modeling the behavior of others, not just the self. When that region was silenced in some animals, those animals became passive, waiting for others to come to them. What happened next was remarkable: their untouched groupmates automatically became more active, compensating so precisely that overall huddle time stayed the same and every animal's body temperature remained stable. No individual animal directed this; the group simply self-corrected. The study also found that animals huddle far more in larger groups, pointing to a kind of collective behavior that only appears when enough individuals are together.
What's next
Researchers now want to understand how the brain weighs an internal signal ("I'm cold") against a social one ("my groupmate isn't moving"), and how those two signals merge into a single decision. They're also investigating how the prefrontal cortex interacts with the hypothalamus, the brain's thermostat, to coordinate these responses.
From the experts
"When one individual in a group is compromised, the group doesn't fall apart—it adapts. That collective resilience is encoded in the brain, and we're now beginning to map the brain circuits behind it," said Tara Raam, first author and co-corresponding author of the study and a postdoctoral scholar at UCLA’s Social Neuroscience Laboratory and. "Our findings suggest that to really understand how the brain controls behavior, we need to look beyond the individual and consider the whole group."
"This research shows that the brain not only helps individuals survive, it also helps groups coordinate collective responses to the challenges we face together," said Weizhe Hong, senior author of the study and professor in the UCLA Departments of Neurobiology and Biological Chemistry. "Understanding how groups think and act as one is one of the most exciting frontiers in neuroscience today."
About the study
Article title: “Cortical regulation of collective social dynamics during environmental challenge” Journal: Nature Neuroscience
DOI: 10.1038/s41593-026-02224-0
Authors: Authors: Tara Raam, Qin Li, Linfan Gu, Gabrielle M. Elagio, Kayla Y. Lim, Jay Y. Taimish, Xingjian Zhang, Norma P. Sandoval, Stephanie Correa and Weizhe Hong Competing interests: The authors declare no competing interests.
