{
  "schema_version": 1,
  "id": "temptation-bundling-exercise-boundary-2020",
  "canonical_url": "https://brali-lifeos.github.io/evidence/temptation-bundling-exercise-boundary-2020/",
  "json_url": "https://brali-lifeos.github.io/evidence/temptation-bundling-exercise-boundary-2020/index.json",
  "decision": "propose-protocol",
  "decision_label": "Protocol candidate",
  "reviewed_at": "2026-09-11",
  "reviewed_by": "Brali Evidence Reviewer",
  "source": {
    "title": "Teaching temptation bundling to boost exercise: A field experiment",
    "url": "https://doi.org/10.1016/j.obhdp.2020.09.003",
    "type": "primary-study",
    "doi": "10.1016/j.obhdp.2020.09.003",
    "citation_text": "Milkman KL, Duckworth AL, Choi J, Laibson D, Madrian B. Organ Behav Hum Decis Process. 2020.",
    "study_design": "Large real-world gym field program containing a preregistered randomized comparison of a free audiobook plus temptation-bundling instruction versus a free audiobook alone, plus a broader comparison with a no-audiobook control. Objective gym check-in data were used before, during and after the intervention.",
    "population": "Adult members of 24 Hour Fitness who enrolled in a four-week exercise-boosting program. The preregistered eligible comparison included 2,334 participants; the broader three-condition analysis included 6,792 participants.",
    "intervention_or_exposure": "A free audiobook paired with explicit instruction and reminders to reserve desired media for gym exercise, compared with audiobook-only and no-audiobook program conditions. All StepUp participants also encountered planning prompts, reminders and small visit-linked rewards.",
    "outcomes": [
      "Probability of at least one weekly gym workout",
      "Average weekly gym visits during the program",
      "Gym attendance after the intervention"
    ]
  },
  "supported_claim": "Pairing a delayed-benefit behavior with a compatible immediate reward can modestly increase exercise participation in some field settings. Brali can offer temptation bundling as a task-initiation experiment, while keeping its strongest empirical anchor in exercise and requiring that the reward not impair the useful activity.",
  "unsupported_or_overstated_claims": [
    "Temptation bundling works equally well for every habit.",
    "The audiobook itself proves the mechanism independent of planning, reminders and other program components.",
    "A reward should always be restricted exclusively to the target behavior.",
    "The technique reliably creates permanent habits.",
    "Adding entertainment is appropriate for driving, complex learning, technical work or exercise where divided attention creates risk."
  ],
  "limitations": [
    "The strongest evidence is concentrated in exercise/gym behavior rather than arbitrary habits.",
    "The large StepUp program included multiple behavior-change components, complicating attribution in broader control comparisons.",
    "The incremental effect of explicit temptation-bundling teaching over receiving the audiobook alone was modest.",
    "Participants self-selected into an exercise-boosting program and may have been more motivated than typical gym members.",
    "The original field experiment showed that effects can decay and be disrupted by context changes such as holidays."
  ],
  "target_hack_ids": [
    "temptation-bundling"
  ],
  "target_protocol_ids": [
    "brali:temptation-bundling"
  ],
  "risk_flags": [
    "health"
  ],
  "notes": "Publish with a compatibility/safety gate and behavior tracking. Keep generalization from exercise to other low-complexity habits explicitly tentative."
}