Bosses who are most conscientious about the fairness of workplace decisions make their workers happier and their companies more productive, but they may be burning themselves out.

A new paper found the act of carefully monitoring the fairness of workplace decisions wears down supervisors mentally and emotionally.  The researchers surveyed 82 bosses twice a day for a few weeks. Managers who reported mental fatigue from situations involving procedural fairness were less cooperative and socially engaging with other workers the next day. 

"Structured, rule-bound fairness, known as procedural justice, is a double-edged sword for managers," said Professor Russell Johnson of the Michigan State University business school. "While beneficial for their employees and the organization, it's an especially draining activity for managers. In fact, we found it had negative effects for managers that spilled over to the next workday.

Johnson said procedural justice is mentally fatiguing is because it requires managers to conform to particular fairness rules, such as suppressing personal biases, being consistent over time and across subordinates, and allowing subordinates to voice their concerns.

"Managers who are mentally fatigued are more prone to making mistakes and it is more difficult for them to control deviant or counterproductive impulses. Several studies have even found that mentally fatigued employees are more likely to steal and cheat."

Prof. Russell Johnson. Credit: Michigan State University

Employees may be concerned about not having personal input into a decision, skeptical about whether accurate information was used to make decisions or resentful over not receiving the same consideration as another more favored employee.

"Essentially managers have to run around making sure their subordinates' perceptions remain positive, whether the threat to the atmosphere of the workplace is real or imagined. Dealing with all of this uncertainty and ambiguity is depleting," Johnson said.

Managers who are fair cannot realistically avoid some burnout, he added. They just need to create situations in which they are better prepared to cope with the fatigue and overcome it.

Tips for managers include getting sufficient sleep, taking short mental breaks during the workday, adhering to a healthy diet and detaching from work completely when outside of the office – for example, not reading email or memos at home after 7 p.m.