4: Key Principle No. 1: Interaction 115

At the market 117

At the urinal 118

In the lecture theatre 121

Complexity vs. complicated 122

Complexity as a way of seeing the world 123

Interactive animals 124

Interactive humans 125

Back to the football 126

Learning from the Mexican wave 127

At the offi ce 128

Meanwhile, somewhere in Aberdeen 129

Summary so far 130

Every day, every day, in every way . . . 130

Crime and punishment 132

New York, New York 133

The physics of crime 135

More crime, less physics 136

Crims, saints and fl oaters 137

Fighting on the beaches (and in the suburbs) 139

The facts 139

Analysis 141

What to do about such riots 143

Markets and interaction 143

Behavioural markets 145

The challenge for market research 146

Issues arising 147

Implications and questions for marketing and business 147