New research links poor sleep to heightened conflict with supervisors and higher-ranking colleagues, with implications for HR wellbeing strategies
Poor sleep causes conflict up the organisational ladder, and new research suggests HR leaders may have a direct role in addressing it.
The finding comes from a series of studies by the Johns Hopkins Carey Business School in Baltimore, Maryland. Collaborating teams at the University of South Carolina and the Walter Reed Army Institute of Research contributed to the work.
Employees who rest poorly are significantly more likely to clash with higher-ranking colleagues than with peers or subordinates. The research draws on data from US Army soldiers, tracing how fatigue shapes conflict across the organisational hierarchy.
The core finding: while poor rest raises the likelihood of friction generally, the sharpest escalation occurs upward. When rest was adequate, conflict remained low regardless of who was involved. When it deteriorated, arguments with supervisors increased far more than disputes between peers.
The full study, Sleep and Strife: The Effects of Sleep on Conflict within Organisational Hierarchy, was published in August 2026.
Why does poor sleep cause conflict with managers?
Brian Gunia is a professor and area chair for management and organisation at the Johns Hopkins Carey Business School. He argues that self-control is the critical mechanism. Interacting with senior colleagues demands more behavioural regulation – suppressing frustration, choosing words with care, and staying within professional norms.
"Avoiding conflict with higher-rank individuals in organizations involves following strict workplace norms," said Gunia. "That requires more self-control, but we know that sleep problems compromise people's self-control."
Because the behavioural standards managing upward interactions are stricter, the impact of depleted self-control is most visible there. Peer-level interactions carry weaker social expectations, so the erosion is less pronounced.
"Employees starved for self-control simply find it harder to follow those workplace norms," Gunia added.
What can HR leaders do about poor sleep causing conflict?
Interpersonal friction, the authors note, damages organisational performance by undermining collaboration – with flow-on effects for morale, productivity, and retention. In high-stakes environments such as healthcare, emergency services, and aviation, the risks are more acute. HR leaders managing teams in safety-critical roles may find that fatigue-related friction is already surfacing in performance data or interpersonal complaints.
"It seems critical for organizations to pull whatever levers they can to support employee sleep," the researchers conclude.
The research points to a specific intervention: sleep leadership. Gunia and colleagues have separately developed and studied this approach, in which managers and HR teams actively encourage healthy rest among their employees. Prior work shows it improves rest quality. Leaders trained in this way may also reduce the upward conflict that threatens team cohesion.
How should organisations act on the findings?
Practical levers include reviewing scheduling and workload expectations, establishing clearer norms around after-hours communication, and incorporating fatigue into employee wellbeing and mental health strategies. Organisations placing heavy demands on staff in high-hierarchy roles may be creating the conditions in which poor sleep causes conflict to escalate.
"Accounting for the possibility of increased conflict should further incentivize organizations to promote healthy sleep patterns or at least to avoid imposing excessive work demands," the study notes.
Managing fatigue risks and supporting employee wellbeing across industries is a growing strategic priority. This research makes the case that poor sleep causes conflict – and that HR leaders are well placed to do something about it.
