40+ Behavioral Science Heuristics for Conversion Optimization
Systematic application of cognitive biases and behavioral principles is the fastest path to better conversion rates. This is the complete library of heuristics used in AI-powered CRO audits.
Category 1: Cognitive Ease and Processing
1. Cognitive Load Reduction
Reduce mental effort required to complete a task. Fewer choices, simpler layouts, clearer copy.
2. Hick’s Law
Decision time increases with the number of options. Limit choices to speed decisions.
3. Miller’s Law
People can hold 7 plus or minus 2 items in working memory. Chunk information into groups of 3-5.
4. Processing Fluency
Easier-to-process information feels more trustworthy. Use simple fonts, clear language, familiar layouts.
5. Serial Position Effect
People remember the first and last items in a list best. Place key information at the start and end.
6. Von Restorff Effect
Distinctive items are remembered better. Make CTAs visually different from surrounding content.
7. Gestalt Principles
Visual grouping affects perception. Use proximity, similarity, and closure to organize information.
Category 2: Trust and Credibility
8. Social Proof
People follow the behavior of others. Show reviews, testimonials, customer counts, and logos.
9. Authority Bias
People trust experts and authoritative sources. Display certifications, awards, media mentions.
10. Bandwagon Effect
“Everyone’s doing it” drives adoption. Show popularity indicators and user counts.
11. Mere Exposure Effect
Familiarity breeds trust. Consistent branding across touchpoints increases conversion.
12. Halo Effect
Positive impression in one area influences perception of others. Professional design builds product trust.
13. In-Group Bias
People trust those similar to them. Show testimonials from customers in the same industry or role.
14. Reciprocity
Giving something first increases willingness to give back. Free trials, valuable content, free tools.
Category 3: Motivation and Desire
15. Loss Aversion
Losses feel 2x more painful than equivalent gains. Frame offers as “don’t miss out” vs “you’ll gain.”
16. Scarcity Principle
Limited availability increases perceived value. Stock counts, time limits, limited editions.
17. Urgency
Time pressure accelerates decisions. Deadlines, countdown timers (when genuine).
18. Endowment Effect
People value things more once they feel ownership. Free trials, “your” plan, customization.
19. IKEA Effect
People value things they helped create. Configuration tools, customization options, quizzes.
20. Goal Gradient Effect
Motivation increases as people get closer to a goal. Progress bars, checklists, step indicators.
21. Zeigarnik Effect
Incomplete tasks create mental tension that drives completion. Unfinished profiles, open carts.
Category 4: Decision Architecture
22. Anchoring
The first number seen influences all subsequent judgments. Show the higher price first.
23. Decoy Effect
Adding an inferior option makes the target option look better. Three-tier pricing with a strategic decoy.
24. Default Effect
People tend to stick with pre-selected options. Set defaults strategically (annual billing, recommended plan).
25. Framing Effect
How information is presented changes decisions. “95% success rate” vs “5% failure rate.”
26. Contrast Effect
Items are judged relative to what’s next to them. Position your offer next to an expensive alternative.
27. Choice Architecture
How options are structured influences selection. Number, order, and presentation of choices matters.
28. Status Quo Bias
People prefer the current state. Reduce switching costs and make transitions seamless.
Category 5: Attention and Perception
29. Visual Hierarchy
Eye movement follows visual weight. Larger, bolder, higher-contrast elements get attention first.
30. F-Pattern / Z-Pattern
Web readers scan in predictable patterns. Place key content along these natural scan paths.
31. Banner Blindness
Users unconsciously ignore ad-like content. Make CTAs look like content, not ads.
32. Attentional Bias
People notice what’s relevant to their current needs. Match content to visitor intent.
33. Change Blindness
People miss changes they don’t expect. Make important updates obvious and prominent.
34. Fitts’s Law
Larger, closer targets are easier to click. Make CTAs big and positioned near the cursor or thumb.
Category 6: Emotion and Psychology
35. Peak-End Rule
Experiences are judged by their peak moment and ending. Make checkout confirmation delightful.
36. Commitment and Consistency
Once people commit to something small, they follow through with larger commitments. Start with micro-conversions.
37. Curiosity Gap
Information gaps drive exploration. Tease value without revealing everything upfront.
38. Paradox of Choice
Too many options cause decision paralysis. Curate and recommend rather than display everything.
39. Sunk Cost Fallacy
Investment of time or effort makes people less likely to abandon. Multi-step forms, quizzes, configurations.
40. Affect Heuristic
Emotions influence rational decisions. Use emotional imagery and storytelling alongside logical arguments.
41. Narrative Bias
Stories are more persuasive than statistics alone. Combine data with customer stories.
42. Autonomy Bias
People want to feel in control. Offer choices, customization, and “your way” messaging.
How to Apply These Heuristics
- Audit your site against each heuristic
- Identify violations — where are you working against human psychology?
- Prioritize fixes using the AXR framework
- Test changes — don’t implement all at once
- Document learnings — build an institutional knowledge base