The Interdisciplinary Handbook of Perceptual Control Theory

The Interdisciplinary Handbook of Perceptual Control Theory: Living Control Systems IV

This new edited, 600-page, volume of contemporary work on PCT across the life & social sciences and engineering, will be published in June 2020 by Academic Press, Elsevier. For further details and orders, please see the flyer.


A theory ahead of its time?

In 1973, William T. Powers published 'Behavior: The Control of Perception'. The book formalised the theory he had been developing since the 1950s, and now it is unifying the physical, life and social sciences. The book is available at

PCT provides a theory about how human beings and other living systems work – how they control what matters to them. Take a look at the video below to get started...

The demonstration above has recently been the topic of research - over 300 people 'fell' for the illusion, revealing the validity of a PCT account of behavior. You can also try out a whole range of interesting ways to illustrate perceptual control on Gary Cziko's website.

This website gives you a glimpse at what a theory called PCT can do to help explain these things, and many, many more...

The idea is simple.

You don’t have to pay for it. It’s for everyone to use.


PCT in action

Take a look at how PCT is being used to develop realistic arm control in robots:


To see a wonderful array of robots implementing PCT, see Rupert Young's website and view his talk at TAROS 2014:




BABCP Special Interest Group

University of Manchester April 2015

The timetable and abstracts are available here. The powerpoint slides for the event are available here. For further information about the BABCP SIG, go to their website.


Past Conferences

The following past Control Systems Group conference papers (2010) are available here:

Fred Good - A Connected School

Bill Powers - The Tank that Filled Itself

McClelland & Worthington - Buying & Selling Simulation

Carey - A Right Turn for Researchers

Finally, please click here to read Kieran Lord's review of the conference.

The proceedings of the 2007 CSG conference at University of Manchester are available here.


Visits to PCTWeb...

PCTWeb has been running since 2009 and receives over 2000 visits per month. The current data for today, yesterday and the total visits since February 2012 are:

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The latest book...

Click here to read more about the latest popular science book on PCT by Rick Marken and Tim Carey. Rick Marken has also produced slides for a book talk delivered at Antioch University.

Coming out in April 2017...

Richard Pfau uses PCT to help understand your own behaviour the behaviour of those around you...

Join a Public List...

If you use PCT in your work or studies then please sign up to our public list by clicking here. The current list is available, updated Jan 2017- here. We are making this available on PCTWeb to show the international uptake and applications of the theory.

There are regular discussions on CSGNet, which is described at The archive of CSGNet discussions is available at

Or you may like to join the Student PCT Facebook Group by clicking the icon below...

Further Introductory Videos on PCT

Rick Marken produced the following talk on PCT at the European Institute for Reality Therapy conference in Bled, Slovenia, October 2016.


In the YouTube video below, Warren Mansell explains the benefits of taking a PCT approach to teaching psychology in this TEDx talk at Burnley College in 2012.


PCT50 Conference, University of Manchester, UK

For the audio & powerpoints of Rick Marken's presentation on research methodology, click here.

Two online videos of Bill Powers' demonstrations:




The Evidence Base for PCT & Mental Health Applications

The current evidence base for PCT, accumulated over the last five decades to the present day, is summarised in a downloadable working document that will be updated regularly pending its publication as a review. Feedback is welcome. A working document of published papers on PCT and its application to mental health is also available here.



This website was designed by Mike Marshall and is maintained by Warren Mansell. If you have any comments, queries or suggestions concerning the website, please find his details here.