• Quick guide to PCT

    Quick guide to PCT

    Perceptual Control Theory (PCT) has been around for over 50 years, leaving a trail of papers, books, websites, posts, conversations, videos all over the web. This is a quick guide to get started with the most basic materials: introductory texts, books, demonstrations, papers, websites and finding others interested in PCT. Welcome! [...]
  • PCT in 11 steps - introduction by Bill Powers

    PCT in 11 steps - introduction by Bill Powers

    Control is a process of acting on the world we perceive to make it the way we want it to be, and to keep it that way. Examples of control: standing upright; walking; steering a car; scrambling eggs; scratching an itch; knitting socks; singing a tune. Extruding a pseudopod to absorb a nanospeck of food (all organisms control, not only human beings). The smallest organisms control by biochemical means, bigger ones by means of a nervous system. [...]
  • A simple introduction to PCT

    A simple introduction to PCT

    A simple start… PCT stands for Perceptual Control Theory. Big words, eh? The ‘big idea’ behind PCT is simple but don’t be surprised if it takes a while to get your head around. This is it…. ‘Behaviour is the control of perception’ That’s it. Or more simply, we do things to get what we want – now that sounds too simple! Let’s take it a step at a time… [...]
  • Once around the loop

    Once around the loop

    Elements of the control loop have been labeled slightly different by different people at different times and for different purposes, whether for a very plain explanation or for more mathematical treatment of the physical functions. Dag Forssell describes the elements of the control loop step by step, as an introduction to the basics of PCT. [...]

Applications of Perceptual Control Theory

Sociology & Philosophy


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. […]

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Sociology & Philosophy

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 […]



Education is about more than teaching. Within education we need to know how to motivate students, how can we maximise the degree to which people learn, and often, how do we manage students or pupils when they don’t want to learn, or they disrupt others? […]

Psychology & Mental Health


In explaining how living things control their perception, PCT is clearly highly relevant to psychology. Contemporary articles are making the case to the wider establishment that closed-loop, circular causality is much closer to how living systems actually function than the approach researchers still use. […]

Economics & Marketing

Economics & Marketing

To manage a successful business, you need to know what people want, how your business is perceived, and how to deal with people. It’s ripe for a PCT approach! […]

Random Selection of books about PCT


PCT Tutorials and Simulations

NOTE: Bill Powers’s work Living Control Systems III : The Fact of Control (2008) with updated Windows programs is recommended. These programs and the book explaining them provide an excellent introduction to PCT. The programs themselves are superior […]

PCT Playlist


IAPCT Conference Playlist

PCT and MOL on Spotify