What Works in Gamification for Health Behavior Change: Effect Sizes from a Meta-Analysis

In 2013, I published a scientific editorial in JMIR Serious Games titled Gamification: What It Is and Why It Matters to Digital Health Behavior Change Developers. It was an invited publication in what has since become a seminal journal in the field. The paper laid out the psychological architecture of gamification, mapped its seven core principles to validated behavior change theory, and made the case for when gamification is and isn’t appropriate for health interventions.

What the editorial didn’t include was hard numbers. To add a practical layer to the theory, I informally cross-referenced the gamification framework against a separate quantitative study: my peer-reviewed meta-analysis on the factors that make online health behavior change interventions work (Cugelman, Thelwall, & Dawes, 2011). That meta-analysis produced effect sizes for dozens of behavior change techniques. By mapping those techniques onto the seven gamification principles, we get a rough but useful picture of which principles carry the strongest behavioral science support.

This is not a formal meta-analysis of gamification specifically. Treat it as an evidence-informed supplement to the original theory paper, a way of putting practical numbers behind the framework.

Proven behavior change principles that work in gamification

The 2011 meta-analysis examined 30 online health behavior change interventions and identified which psychological techniques produced measurable changes in behavior. The 2013 editorial identified seven core principles that make gamification work and mapped each one to related behavior change techniques from the research literature.

The cross-reference here takes that mapping one step further by attaching the effect sizes from the meta-analysis to each technique. Effect sizes are reported as Cohen’s d, classified using Lipsey & Wilson (2001) benchmarks: d below 0.2 is negligible, 0.2 to 0.5 is small, 0.5 to 0.8 is medium, and 0.8 and above is large. Techniques marked with an asterisk (*) were borderline statistically significant in the original study and should be treated with caution, though they may still be useful in some contexts.

Where a gamification principle maps to multiple techniques, all mapped techniques are listed. The goal is to show relative strength across the framework, not to imply that every technique is equally practical for every intervention.

The seven principles of gamification

From the 2013 JMIR editorial, the persuasive architecture of gamification rests on seven core principles:

  • Goal setting. Users commit to achieving a goal.
  • Overcoming challenges. Users face progressively difficult challenges that build capacity and skill.
  • Receiving feedback. Users receive constant feedback on their performance.
  • Reinforcing behavior. Users gain rewards for successful behavior or outcomes.
  • Comparing progress. Users monitor their progress relative to others.
  • Interacting with others. Users operate in a social environment.
  • Playing and having fun. Users experience a genuinely playful environment.

Each principle maps to validated behavior change techniques with measurable effect sizes, with one notable exception. More on that below.

Effect sizes by gamification principle

The charts below show the behavior change techniques mapped to each gamification principle, with effect sizes from the meta-analysis listed in descending order within each principle.

Negligible (d < 0.2)
Small (0.2–0.5)
Medium (0.5–0.8)
Large (0.8+)

0.1.2.3.4

1. Goal setting

Consequences of behavior (general)

.306
Behavioral contract

.275
Beliefs about consequences

.269
Consequences for the individual

.259
Setting behavioral goals

.240
Building an action plan

.240
Experiencing fear

.193
Prompts to review goals *

.138

2. Overcoming challenges

Time management skills

.344
Self-talking strategies

.319
Communication skill training *

.295
Knowledge on the behavior

.291
Deeper understanding of behavior

.274
Identifying barriers and solving problems

.224
Where and when to perform behavior

.218
Observing others demonstrate

.218
Instruction on how to perform

.212
Restructure environment *

.189
Manage stress *

.165

3. Receiving feedback

Prompts to self-monitor outcome

.261
Prompts to self-monitor behavior

.225
Aids to memory and decision making

.198

4. Reinforcing behavior

Rewards contingent on success

.291
Information about others’ approval

.206

5. Comparing progress

Normative information about others

.246
Comparison against others

.226

6. Interacting with others

Planning for social support

.250

7. Playing and having fun

No mapped techniques in the original literature.

Effect sizes (Cohen’s d) classified per Lipsey & Wilson (2001). * Borderline statistical significance. Scale represents d from 0 to 0.4.

What the evidence suggests

A few patterns stand out from this informal mapping.

Overcoming challenges has the broadest and strongest support across all seven principles. The techniques mapped to it span skill building, knowledge, barrier identification, and self-regulation, and several produce effect sizes in the .29 to .34 range. If you’re designing a health intervention with gamification in mind, building in meaningful challenge progression is probably the highest-value investment.

Goal setting and reinforcement also show consistent support. Behavioral contracts, consequence framing, and contingent rewards all cluster around the .25 to .30 range. These are well-understood techniques with a solid evidence base behind them.

Feedback and social comparison are more modest but still meaningful. Self-monitoring prompts and normative comparison techniques sit in the .22 to .26 range. Small effects that add up when combined with stronger techniques.

The fun and playfulness gap is the most notable finding in this mapping. Not because fun is ineffective, but because we don’t have good quantitative evidence for it in health behavior change contexts. Given how central playfulness is to the gamification framework, this is a genuine research gap. The field has since paid more attention to this question, and the direction of the evidence is clear: if your gamified intervention isn’t genuinely enjoyable, it’s missing the point.

One important caveat: all effect sizes here are small by conventional standards. Health behavior change is hard. These numbers reflect modest but real impacts from individual techniques. The power of gamification comes from combining these principles into a coherent persuasive architecture, not from deploying any single technique in isolation.

Checklist for evaluating if gamification is suitable to your intervention

The evidence clearly shows that gamification can work. But it’s only suitable for particular contexts. In applied behavioral science, choosing the wrong theoretical framework doesn’t just make an intervention less effective. It can cause it to backfire entirely. Before committing to gamification, it’s worth doing a quick assessment to see if it’s actually the right fit for your goals and audience.

Work through the following questions. If you’re finding more hesitation than confidence, a different persuasive architecture may serve you better.

  • What psychological and behavioral outcomes are you targeting?
  • What types of beliefs, attitudes, or behaviors need to shift to achieve those outcomes?
  • Is gamification compatible with your target audience’s existing behaviors and habits?
  • Will your audience find the game-based rewards meaningful?
  • Will your audience interact with each other socially within the intervention?
  • How well does your theory of change align with the seven gamification principles?
  • Is your technology platform adaptable to gamification mechanics?
  • Can you make it genuinely fun?

References

  • Cugelman, B. (2013). Gamification: What it is and why it matters to digital health behavior change developers. JMIR Serious Games, 1(1), e3. https://doi.org/10.2196/games.3139
  • Cugelman, B., Thelwall, M., & Dawes, P. (2011). Online interventions for social marketing health behavior change campaigns: A meta-analysis of psychological architectures and adherence factors. Journal of Medical Internet Research, 13(1), e17. https://doi.org/10.2196/jmir.1367
  • Lipsey, M., & Wilson, D. (2001). Practical meta-analysis. Sage.