Classic research comparing children already engaged voluntarily and enthusiastically in a drawing activity found that introducing an external reward specifically for that same drawing activity reduced the children's subsequent voluntary engagement in drawing once the external reward was later removed, compared to children who continued drawing without ever having an external reward introduced at all — a counterintuitive finding called the overjustification effect: adding an external reward to an already intrinsically enjoyed activity can undermine, rather than simply add to, the original intrinsic motivation.
What the underlying mechanism is thought to be
One leading explanation proposes that introducing an external reward changes how a person interprets their own reason for engaging in an activity — rather than continuing to interpret their engagement as reflecting genuine personal enjoyment, they begin to attribute at least part of their engagement to the external reward instead, and once that external reward is removed, the activity has lost some of the genuine, purely intrinsic motivational appeal it originally held, since part of the original motivation has effectively been reattributed to the now-absent external incentive.
Why this has direct, practical implications for workplace incentive design
An employee who genuinely, intrinsically enjoys a specific aspect of their work — mentoring junior colleagues, a particular creative or problem-solving task — and is then offered a specific financial bonus tied directly to that same activity, risks experiencing exactly the overjustification effect the underlying research describes, potentially reducing their genuine intrinsic engagement with that activity once the bonus is reduced, removed, or simply no longer feels sufficiently rewarding on its own external terms.
Why this effect specifically concerns tasks with genuine pre-existing intrinsic motivation
The overjustification effect's documented risk specifically applies to tasks an employee already found genuinely intrinsically enjoyable or motivating before any external reward was introduced — introducing incentives for tasks lacking this pre-existing intrinsic appeal in the first place doesn't carry this same specific undermining risk, since there's no pre-existing intrinsic motivation present to be undermined or crowded out by the newly introduced external reward.
Why this creates a genuine, counterintuitive design tension for incentive programs
An organization's natural instinct to reward and reinforce behavior it wants to encourage, including behavior employees already engage in willingly and enthusiastically, can specifically backfire when applied to exactly this kind of already-intrinsically-motivated behavior, creating a genuine design tension: the behaviors an organization might most want to formally recognize and reward through incentive programs are sometimes precisely the behaviors where introducing a formal external incentive carries the greatest documented risk of undermining the pre-existing intrinsic motivation.
What actually helps navigate this tension in incentive program design
Reserving direct financial incentives specifically for tasks and behaviors that don't already carry strong pre-existing intrinsic motivation, while using non-monetary recognition — genuine acknowledgment, expressed appreciation — for already intrinsically motivated behavior, avoids the specific overjustification risk associated with converting an already-enjoyed activity into an externally, financially incentivized one. Where a financial incentive for an already intrinsically motivated activity is genuinely necessary for other organizational reasons, structuring it as a less contingent, more unconditional form of recognition, rather than a tightly performance-contingent bonus specifically tied to that exact activity, appears to carry somewhat lower overjustification risk based on related research.
What this means for organizations designing employee incentive and recognition programs
- Identify which behaviors employees already find genuinely intrinsically motivating before introducing a tightly tied financial incentive specifically targeting those behaviors
- Reserve direct, performance-contingent financial incentives primarily for tasks lacking strong pre-existing intrinsic motivation
- Use non-monetary recognition for already intrinsically motivated behavior, avoiding the specific overjustification risk tightly contingent financial rewards carry
- Where a financial incentive for an already-enjoyed activity is genuinely necessary, consider less tightly contingent structures over a direct, activity-specific performance bonus
The overjustification effect is a genuinely counterintuitive but well-documented finding — the instinct to formally reward behavior employees already do willingly can, in exactly this specific circumstance, undermine the very motivation an organization was trying to reinforce, which is precisely why incentive design requires distinguishing between behaviors that already carry genuine intrinsic appeal and those that don't.