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Evil by Design: Interaction Design to Lead Us into Temptation



Evil by Design: Interaction Design to Lead Us into Temptation

Chris Nodder

ISBN: 978-1-118-65481-1 June 2013 320 Pages


How to make customers feel good about doing what you want

Learn how companies make us feel good about doing what they want. Approaching persuasive design from the dark side, this book melds psychology, marketing, and design concepts to show why we’re susceptible to certain persuasive techniques. Packed with examples from every nook and cranny of the web, it provides easily digestible and applicable patterns for putting these design techniques to work. Organized by the seven deadly sins, it includes:

  • Pride — use social proof to position your product in line with your visitors’ values
  • Sloth — build a path of least resistance that leads users where you want them to go
  • Gluttony — escalate customers’ commitment and use loss aversion to keep them there
  • Anger — understand the power of metaphysical arguments and anonymity
  • Envy — create a culture of status around your product and feed aspirational desires
  • Lust — turn desire into commitment by using emotion to defeat rational behavior
  • Greed — keep customers engaged by reinforcing the behaviors you desire

Now you too can leverage human fallibility to create powerful persuasive interfaces that people will love to use — but will you use your new knowledge for good or evil? Learn more on the companion website,

Foreword xi

Introduction xiii

Evil designs and their virtuous counterparts xiii

Pride 1

Misplaced pride causes cognitive dissonance 1

Provide reasons for people to use 3

Social proof: Using messages from friends to make it personal and emotional 5

Dispel doubt by repeating positive messages 7

Personal messages hit home 11

Gain public commitment to a decision 16

Change opinions by emphasizing general similarities 19

Use images of certification and endorsement 22

Closure: The appeal of completeness and desire for order 25

Help people complete a set 26

Pander to people’s desire for order 32

Manipulating pride to change beliefs 35

Sloth 39

Desire lines: From A to B with as few barriers as possible 39

Path of least resistance 41

Reduced options and smart defaults smooth the decision process 44

Provide fewer options 45

Pre-pick your preferred option 50

Make options hard to find or understand 53

Negative options: Don’t not sign up! 56

Sloth: Is it worth the effort? 64

Gluttony 67

Deserving our rewards 67

Make customers work for a reward 69

Consider a small reward rather than a big one 72

Hide the math 75

Show the problems 78

Escalating commitment: foot-in-the-door, door-in-the-face 84

Foot-in-the-door 84

Door-in-the-face 87

Present hard decisions only after investment 90

Invoking gluttony with scarcity and loss aversion 93

The Tom Sawyer effect 93

Instill doubt to prevent cancellations 96

Impatience leads to compliance 99

Self-control: Gluttony’s nemesis 101

Anger 103

Avoiding anger 104

Use humor to deflect anger 104

Avoid overt anger with a slippery slope 107

Use metaphysical arguments to beat opponents 112

Embracing anger 117

Use anonymity to encourage repressed behaviors 119

Give people permission 124

Scare people (if you have the solution) 129

Using anger safely in your products 134

Envy 137

Manufacturing envy through desire and aspiration 138

Create desirability to produce envy 138

Create something aspirational 140

Make people feel ownership before they’ve bought 145

Status envy: demonstrating achievement and importance 150

Create status differences to drive behavior 151

Emphasize achievement as a form of status 154

Encourage payment as an alternative to achievement 156

Let users advertise their status 159

Let people feel important 161

Manufacturing and maintaining envy in your products 166

Lust 169

Creating lust: Using emotion to shape behavior 169

Say “I love you” 170

Be the second best 174

Frame your message as a question 178

Create an in-group 182

Controlling lust: Using desire to get a commitment 185

Give something to get something 186

Make something free 190

Sell the intangible value 195

Make a request in order to be seen more favorably 198

Lustful behavior 201

Greed 203

Learning from casinos: Luck, probability, and partial reinforcement schedules 204

Use a partial reinforcement schedule 208

Make it into a game 211

Customers should “win” rather than “finish” or “buy” 214

Further inflate people’s (already overconfident) feelings of skill and mastery 217

Make rewards seem due to skill, not luck 221

Create a walled garden 225

Anchoring and arbitrary coherence 227

Own the anchor 229

Move from money to tokens 233

Encourage breakage 236

Make it expensive 238

Show your second-best option first 240

Break coherence to justify prices 243

Feeling greedy? 246

Evil by Design 249

Should you feel bad about deception? 250

Should you feel bad about using the principles in this book? 254

Be purposefully persuasive 258

The Persuasive Patterns Game 259

References 269

Index 297