Dave describes the Hawthorne effect through an IBM lab where productivity rose when lighting was increased and also when it was decreased. Dave introduces complex adaptive systems and says a complex system does not have linear causality. Dave identifies himself as the chief scientific officer of Cognitive Edge and says its work applies natural science to social systems. Dave groups Lean Startup with examples of case-based approaches that start with a hypothesis and find examples to validate it. Dave groups work by Malcolm Gladwell with highly selective examples that ignore cases that do not fit. Dave explains the butterfly effect as small things combining to produce a major impact without the same outcome happening the same way twice.