Sociology & Politics


Sociology involves understanding how people behave in groups, including how they communicate and interact with one another. PCT provides a way to understand how people’s goals operate when in groups, and we can use computers to model how more than one control system interacts in a group setting. The Crowd Demonstration link illustrates this. Each of the moving circles on the screen is an ‘agent’ who has two control systems – one to be as close as possible to its target, and another to be beyond a certain distance from other ‘agents’. Some of the demo programs online show how changing the numbers and control system settings of the agents can lead to a huge range of different social scenarios – from the classic duckling-following-parent to large scale crowd behaviour.

Clark McPhail, Kent McClelland and several other prominent sociologists have made a convincing case that PCT can be used to understand sociology. Further sociologists, such as David Heise, have incorporated PCT into ‘affect control theory’, which focuses on how people’s behaviour is a means of maintaining affect (e.g. mood) within certain reference values.

Recently, Dan Miller has written a wonderful online essay about the relationship between PCT and symbolic interactionism, as described by Mead & Goffman. Click here to read it. There are also clear parallels between PCT and the radical constructivism of Ernst von Glasersfeld, described here in a short article by Bill Powers.

Warren Mansell has recently produced a statement about the England riots in 2011 based on PCT. For a full PCT approach to understanding rioting, see McPhail (2005).


Environmental Stability

A comprehensive introduction to PCT and its implications for the social and physical environment, on a global scale, are described in an online article by Kent McClelland. There are also a number of online articles that relate PCT to environmental issues: e.g. Lenk (2009), Lengevin et al. (2015) & Lengevin et al. (2014). These include applications to maintaining homeland security and applying counter-terrorism measures (Bank, 2002) and applications for water conservation (Henderson, 2016).


At present, the application of PCT to Law is at its early stages. Hugh Gibbons is one exception. He has co-authored a biological model of human rights based around the tenets of PCT and he also illustrates a case using PCT in this book, "The Death of Jeffrey Stapleton", published online.

Politics & Philosophy

PCT takes a strongly scientific approach to human nature. It proposes that people and other living systems are purposeful – and that the systems that are responsible for purposeful action are explainable in mechanistic terms. The stance is reminiscent of Aristotle's hierarchy of goods. PCT also takes the paradigm of model-building within physics and engineering and applies it to biology and psychology.

The philosopher Thomas S. Kuhn expressed his praise over Powers (1973) book: "this manuscript is among the most exciting I have read in some time; the achieved synthesis is thoroughly original."

In a new book, Dialogue Concerning the Two Chief Approaches to a Science of Life, Dag Forssell explains the great importance of PCT as a 'true' science within psychology. Yet the debate continues - see the discussion about PCT having claims that are too bold on the website Lesswrong. A recent student research project documents the obstacles to learning and accepting PCT within university education.

Powers’ approach has major implications for key areas of philosophy and politics:

Does science interface with religion?

Read Lynndal Daniels' blog on PCT and Buddhism.

What is knowledge?

Philip Jerair Yeranosian (2014) has written a thorough examination of the nature of behaviour, intelligence and knowledge in this article published at PCTWeb.

What is consciousness?

What is ‘will’? Can we model 'volition'?

Mark Olson approaches this issue from a PCT perspective in his Masters thesis. Also, the book 'Volitional Action: Conation and Control' provides a range of articles on the topic.

Can we explain political catastrophes through the drive for power and control?

What is the nature of reality?

See Martin Taylor's (2013) comments on this topic.

How do we best test a scientific theory?

The links on the right provide just some of the essays on these topics that are available.

Rick Marken takes a visionary approach in an online article in which he imagines a future society that embraces PCT.

In March 2011, Steve Hayes met Bill Powers and they compared views on 'functional contextualism' and PCT. This discussion is now available online.