Concept
Emergence
Also: Emergent behaviour
Patterns and properties of a whole that arise from the interactions of its parts and cannot be found in, or predicted from, any part alone.
Traffic jams, market prices, team culture and the atmosphere on a festival campsite are emergent: nobody designed them and nobody controls them, yet they are real and shape what people do. In the complex domain you cannot plan emergent outcomes, but you can influence the conditions — the constraints and interactions — from which they arise.