When unexpected work falls through the cracks—a sick colleague, a demanding client, or a last-minute project—managers need someone to pick up the slack. Intuitively, they look for the person who won't mind. But a compelling new study reveals that this well-intentioned instinct is actually a management trap: by consistently assigning extra, unglamorous work to the employees who love their jobs the most, managers are inadvertently driving their best people to quit.
The Habit of the "Helper"
Consider a scenario from a recent *Organization Science* study: A finance manager needs someone to take notes at a crucial weekly meeting. She immediately thinks of a specific team member known for helping out and "not appearing to mind."
She isn't alone in this habit. Lead researchers Sangah Bae of Northeastern University and Kaitlin Woolley of Cornell University conducted 10 separate experiments involving over 4,300 managers and employees. They found a pervasive pattern: managers consistently delegate unwanted, extra tasks to the employees who display the most enthusiasm for their core roles, until those high performers are carrying a vastly disproportionate share of the team's grunt work.
The Flawed Logic of "Motive Oversimplification"
Why do managers keep making this mistake? The researchers point to a cognitive bias they call "motive oversimplification." This occurs when a manager takes one true trait about an employee—say, their passion for their main job—and falsely assumes it applies to everything else about them.
When faced with unplanned work, managers quickly narrow their choices down to a few people and decide on the spot, rarely checking if that same person handled the last few extra assignments. They mistakenly believe that an employee's enthusiasm will act as a shield against burnout.
The data proves this assumption dead wrong. When asked to take on tedious, unrelated tasks, the enjoyment of enthusiastic employees plummeted from 5.19 to 2.49 (on a 7-point scale). Meanwhile, less invested coworkers experienced a much smaller dip in satisfaction.
More importantly, enthusiasm offered no protection against exhaustion. Both the enthusiastic and the less invested employees reported nearly identical burnout scores (4.86 vs. 4.93) when saddled with the extra work. Passion alone cannot soften the burden of an overloaded plate.
The High Cost of an Uneven Workload
Left to their own devices, managers rarely break this habit. When researchers observed real managers making delegation choices over a full workweek, they still assigned extra work to the enthusiastic employee 61% of the time, even on their most "balanced" days.
This persistent unevenness comes at a steep price. When enthusiastic employees are given an unfair share of extra work, their likelihood of looking for a new job jumps by nearly 40%. (Conversely, overworking less invested employees doesn't significantly change their turnover intentions). Ultimately, the company loses the exact people it can least afford to lose.
Furthermore, financial incentives don't even mitigate the damage. In one experiment, even when an enthusiastic employee's bonus was tied to their core performance, they missed the mark 69% of the time. Their actual work didn't suffer in quality; they simply ran out of time because their manager had siphoned off their capacity for unrelated tasks.
Two Simple Fixes
Reversing this destructive pattern doesn't require complex new HR software or heavy administrative overhead. The researchers identified two simple, highly effective interventions:
1. **Batch assignments:** Instead of doling out extra tasks one by one as they arise, managers should assign all anticipated extra work at once. This forces them to see the cumulative burden and stops them from defaulting to the same person.
2. **Educate on burnout:** Simply providing managers with a brief, clear explanation that loving a job does not make an employee immune to burnout drastically changes their behavior. After reading this, managers chose the enthusiastic employee no more often than a coin flip.
Crucially, both of these interventions must be applied *before* the delegation decision is made. Once the extra work is assigned, the damage to the employee left holding the bag is already done.