Article Text

Download PDFPDF

Complexity made simple
  1. John Launer
  1. Associate Editor, Postgraduate Medical Journal, London WC1H 9JP, UK
  1. Correspondence to Dr John Launer, Associate Editor, Postgraduate Medical Journal, London WC1H 9JP, UK; johnlauner{at}

Statistics from

If you read almost any healthcare journal these days, you will find the concept of complexity cropping up more and more. The study of complex adaptive systems, also known as complexity science, is burgeoning, along with examples of its relevance to health care. There are dozens of different accounts of complexity on offer and some of these are themselves formidably complex, so it is easy to find them off-putting. In this article, I want to propose the idea that the fundamentals of complexity are in fact extremely simple. Indeed, I would like to suggest that complicated descriptions of complexity may fail to capture its most important qualities, and that simple ones, especially those that use metaphor and appeal to intuition, may be better ways of doing so.

Two common sayings probably sum up all of complexity theory more concisely than any other formulation. One is the expression ‘the law of unintended consequences.’ This imaginary law encapsulates what everyone already knows about complexity even without realising it. Our everyday experience is that anything we attempt to do, either at work or in our daily lives, can result in consequences we never foresaw. The reasons for this are legion, but commonly they include an incomplete prior assessment of the circumstances, the contrary wishes and actions of other individuals, random accidents, or a change in the prevailing context. These are all typical features of complex systems, from teams and hospitals to families and societies, and the processes that take place in them.

This negative expression also has a corollary, in another common statement ‘the whole is more than …

View Full Text

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.