Motivation & Behavior
Why users start, continue, and return. Use for engagement, onboarding, habit-building features, and retention — with the ethics file as a mandatory companion (Persuasion, Ethics & Dark Patterns).
Card A — buy 8, get one free
Card B — buy 10, get one free (2 stamps “on us”)
Nunes & Drèze (2006): an endowed head start increases completion — the effect is in the framing, not the economics. Ethics test: a head start is fair when the underlying deal is real (8 purchases either way); it turns manipulative when the endowment disguises a worse deal or an illusory reward.
Fogg Behavior Model (B = MAP)
A behavior occurs when Motivation, Ability, and a Prompt converge (Fogg, 2009). Design implications:
- When a desired action isn't happening, increasing ability (making it easier) is usually more reliable than pumping motivation (copy, badges).
- Prompts only work above the "action line": a prompt to an unable or unmotivated user is just annoyance (most notification spam fails here).
- Sequence: make it tiny first (Fogg's "tiny habits"), prompt at the moment of highest ability/motivation, then grow the ask.
Self-Determination Theory (Deci & Ryan)
Durable intrinsic motivation rests on three needs:
- Autonomy — feeling in control: choices, customization, skippable flows, "not now" options. Undermined by forced tutorials and nagging.
- Competence — feeling effective and growing: clear goals, immediate feedback, appropriate challenge, visible progress and mastery.
- Relatedness — connection to others: community, sharing, collaboration. Key caution: extrinsic rewards can crowd out intrinsic motivation for already-interesting activities (the overjustification effect; Deci, Koestner & Ryan 1999 meta-analysis) — points and streaks bolted onto meaningful activity can backfire.
Flow (Csikszentmihalyi, 1990)
Deep engagement occurs when challenge matches skill, goals are clear, and feedback is immediate. UX levers: ramp difficulty with skill (progressive feature revelation), remove interruptions during focused tasks, keep feedback tight (<1 s), and give a clear next action.
Habit loops & variable reward
Habits form around cue → routine → reward loops; variable (unpredictable) rewards produce especially persistent behavior (operant conditioning, Skinner; Ferster & Skinner 1957 reinforcement schedules). Product framings: Eyal's Hook Model (trigger → action → variable reward → investment, 2014) and Duhigg's habit loop (2012). Ethical line: use these to help users build habits they want (exercise, learning, saving), not to farm compulsive checking — see the ethics file.
Goals & progress
- Goal-gradient effect: effort increases near completion (Kivetz, Urminsky & Zheng 2006); endowed progress (an artificial head start) increases completion (Nunes & Drèze 2006) — a 10-stamp card with 2 pre-stamped beats a fresh 8-stamp card.
- Zeigarnik effect: open loops nag at memory. Caveat: the classic 1927 finding has a mixed replication record; treat it as a design heuristic (make open loops visible — checklists, resumable drafts, "3 steps left"), not a law.
- Fresh-start framing: people are more likely to begin goal pursuit at
temporal landmarks (Mondays, new year, birthdays) (Dai, Milkman & Riis
- — time re-engagement prompts accordingly.
- Implementation intentions ("when X, I will Y") massively raise follow- through vs. vague goals (Gollwitzer 1999) — let users schedule the action, not just intend it.
Effort, ownership & the IKEA effect
Labor leads to love: people value things more when they helped build them, provided the effort succeeds (Norton, Mochon & Ariely 2012 — the effect disappears when the build fails or is dismantled). UX applications: light-touch setup/customization during onboarding (pick topics, name the workspace, arrange the dashboard) increases attachment and retention; the condition is that the effort must produce a visible, working result quickly. Related: effort justification (Aronson & Mills 1959). Don't weaponize it — adding pointless effort to inflate perceived value fails the ethics tests in Persuasion, Ethics & Dark Patterns.
Gamification: what the evidence says
Reviews of gamification studies (Hamari, Koivisto & Sarsa 2014; later meta-analyses) find mostly positive but modest and strongly context-dependent effects: outcomes depend on the users, the activity, and implementation quality; many studies are short (novelty effects) and methodologically weak. Points/badges/leaderboards work best when they make real progress and competence visible (SDT-aligned); leaderboards can demotivate everyone below the top ranks; rewards bolted onto already-meaningful activity risk overjustification (above). Design gamification around competence feedback, not extrinsic loot.
Onboarding motivation
Show value before asking for effort: minimize steps to the "aha" moment; defer registration/permissions until their benefit is evident (Apple HIG explicitly: ask for permissions in context, when needed, with the reason).
Sources
- Fogg, B. J. (2009). "A behavior model for persuasive design." Persuasive '09 (ACM); Fogg (2019). Tiny Habits.
- Ryan, R. M. & Deci, E. L. (2000). "Self-determination theory…" American Psychologist, 55(1); Deci, Koestner & Ryan (1999). Psych. Bulletin.
- Csikszentmihalyi, M. (1990). Flow. Harper & Row.
- Ferster, C. B. & Skinner, B. F. (1957). Schedules of Reinforcement.
- Eyal, N. (2014). Hooked. Portfolio; Duhigg, C. (2012). The Power of Habit.
- Kivetz, Urminsky & Zheng (2006). JMR; Nunes, J. & Drèze, X. (2006). "The Endowed Progress Effect." JCR, 32(4); Dai, Milkman & Riis (2014). "The Fresh Start Effect." Management Science, 60(10).
- Zeigarnik, B. (1927). Psychologische Forschung — original; later replications mixed.
- Norton, Mochon & Ariely (2012). "The IKEA effect." J. Consumer Psychology, 22(3); Aronson & Mills (1959). JASP.
- Hamari, J., Koivisto, J. & Sarsa, H. (2014). "Does gamification work?" Proc. HICSS.
- Gollwitzer, P. M. (1999). "Implementation intentions." American Psychologist, 54(7).
- Apple HIG — Onboarding; Privacy (requesting permissions in context).