Summary
A complex adaptive system is one made of many interacting parts that keep adjusting to one another, so the behaviour of the whole can’t be predicted from the parts. Cities, markets, ecosystems and the immune system are examples. The sociologist Walter F. Buckley coined the term in 1968; it now names a loose field more than a single theory. John H. Holland described such systems as having many components that “interact and adapt or learn”.
Dave Snowden offers a working distinction. Something complicated can be unfolded and stay much the same; something complex is entangled, and untangling it makes something different. Such systems can be influenced but not precisely controlled.
Rationale
Part 1 draws its humility partly from complexity science: “tracing a straight line from intervention to outcome doesn’t seem to be possible”. We interviewed Snowden, and we read culture as a system of this kind.