But the Role Doesn't
After two terrorist attacks in France — Nice (2016) and Carcassonne (2018) — the firefighter departments involved wanted to understand why some of their people developed severe PTSD symptoms while others, exposed to the same events, did not.
The assumption going in was straightforward: more exposure to the attack means more trauma. But the data told a more complicated — and more useful — story.
Working with 186 firefighters across both departments, we assessed PTSD symptoms using validated clinical instruments (PCL-S) collected 3 to 6 months after each event. We combined confirmatory factor analysis, exploratory factor analysis, cluster analysis, and structural modeling to identify the underlying patterns — not just who was affected, but why, and what organizational factors predicted risk.
Rather than assuming existing PTSD models from the literature would fit our population, we let the data speak first. What emerged was a two-factor structure — a vigilance dimension (intrusive thoughts, flashbacks, hyperarousal) and an emotion dimension (numbness, estrangement, loss of meaning) — that described this population better than any of the eight established models we tested.
We then mapped these symptom profiles against organizational variables — rank, occupational status, exposure level, age — to identify which factors actually predicted who was at risk.
Exposure level was the primary driver of PTSD symptoms, as expected. The more directly involved a firefighter was in the rescue operation, the higher their symptom load.
But rank mattered independently of exposure. And that is where the organizational story begins.
Firefighters I/II — the hands-on, operational rank — showed significantly higher vigilance symptoms than officers and medical staff, even when their exposure level was identical. Same scene. Same duration. Same horrors. Different response.
Occupational status — professional versus volunteer — did not predict symptom profiles directly. Age played a mild protective role: older firefighters showed slightly lower vigilance symptoms, consistent with evidence that experience and emotional regulation capacity buffer acute stress responses.
When professionals are deployed to situations that require them to act outside their trained role — whether that is a firefighter managing mass civilian casualties, a nurse being asked to make command decisions, or an engineer sent into client negotiation without preparation — the psychological risk increases independently of the objective danger involved.
The data suggest a clear principle:
Role-task alignment is a psychological safety issue, not just an operational efficiency issue.
Sending someone into a high-stress situation where their trained mental model does not match the required behavior does not just reduce performance. It increases the probability of lasting psychological harm.
Three concrete implications that apply well beyond firefighting.
This was not a controlled lab study. It was field research conducted in the direct aftermath of real traumatic events.
The findings are messy in the way real data always is — small sample, missing values, confounding variables between the two events. We were transparent about all of this in the published paper. This is not a definitive causal model.
What the work demonstrates is the ability to enter a high-stakes, emotionally charged organizational environment; design a rigorous study under difficult conditions; extract meaningful signal from noisy data; and translate that signal into recommendations that can actually change how an organization protects its people.
The firefighters were the context. The capability is applicable anywhere people face high-pressure role demands — healthcare, emergency services, military, and any organization navigating rapid change where people are asked to do things their role did not prepare them for.