Emergent behavior

Definition
Emergent behavior is

"that which cannot be predicted through analysis at any level simpler than that of the system as a whole."

Overview
"Large software and network systems demonstrate emergent behavior and the need to test for these types of behavior is now well understood. . . . Emergent behavior is not necessarily bad &mdash; for example, a colony of ants demonstrate greater capabilities and intelligence than individual ants &mdash; but understanding these emergent behaviors is critical to enable successful large scale system deployments. . . ."