My normal working day involves something like this. I record a video on Instagram explaining Discovery Talk, which is a way that anyone can learn to help someone else solve a problem on their mind through simple questioning. Next, I have a meeting about a new robotics project with the head of the university electrical engineering department to see if certain software designs can lead robots to balance more accurately and effortlessly. After lunch, I talk to a manager of a social enterprise in Salford about his initiative to train carers in ways of communicating with their relative with dementia in a way that enhances the quality of their relationship. Just before tea, I discuss with a leading sociologist the core principles to improving mediation between conflicting parties within legal disputes and international conflicts.

These days, science encourages us to be specialists. Yet, I have never seen things this way. I grew up fascinated with nature, but also intrigued by the brain, computer programming, creative writing, acting, music, art, acting, and, ultimately mental health and well-being.

So, when it came to my day job – academic research – I wanted to find a scientific theory that could encompass all these domains. A tall order you might think? But, of course, before the 20^th century, and going back to the Renaissance Period, the sciences, art and humanities tended to be taught, discussed and practised together. When I stumbled upon Perceptual Control Theory (PCT) in the late 1990s, I knew I had found a theory that fitted the bill for the contemporary world. This theory was developed by the medical physicist and engineer, William (Bill) T. Powers, over 60 years ago.

Fast-forward to the present, and I have just finished editing a book, The Interdisciplinary Handbook of Perceptual Control Theory: Living Control System IV. Bill Powers sadly passed away on Friday 24^th May 2013, and it was his wish for this book to be produced to try to see through his life’s work. He had already written a series of detailed volumes on the theory, including Behavior: The Control of Perception in 1973, and Living Control Systems I, II, and III, throughout the 1980s and 90s. Along the way, Bill has inspired researchers and practitioners across a huge diversity of disciplines to transform their approach based on his theory. I have been tracking these developments over the last 20 years or so, and now, it has been an immense privilege to put together a 600-page volume written by many of these international leaders.

Bill Powers’ most unique insight was twofold.

First, life is the control of input.

Second, this mechanism of control can be specified, in precise detail.

Whilst many in the social sciences were trying to explain how ‘stimuli’ could be processed, and the environment modelled, to lead to the correct ‘response’, Powers was describing how a continuous, dynamic process that he inherited from his life as an engineer – negative feedback control – could render cognitive and behavioural theories redundant. According to Powers, control is managed by varying outputs ‘on-the-fly’ to keep inputs at a desired value. No need for prediction or detailed computation. A classic example is the ‘gaze heuristic’ that has been modelling using PCT; it means that to intercept an object like a flyball in a baseball match, you should alter your actions in the moment to keep the image of the ball at the centre of your field of vision moving upwards at a constant speed. No processing of the physics of your body, the ball or the surroundings, is required.

The word ‘desire’ in PCT itself is deliberate. For Powers, the intention, will, volition, purpose and desire we ascribe to other people – is an inherent, biologically inherited mechanism, shared by all life. It is enhanced with learning. Purposiveness allows living things to defy the cause-and-effect arrow of nature to varying degrees, by specifying their own sensory input, environments, and ultimately, in humans and maybe some other animals, their own conscious experiences.

Powers’ second insight that the mechanisms of control could be specified then led him on a path of discovery to specify each of the components that, put together, redescribed human psychology. From here, the applications across disciplines bore fruit.

Our book starts with explanations of PCT that show its uniqueness within contemporary psychology, engineering, mathematical logic, and neuroscience. Then follows a series of chapters on the contribution of PCT to understanding animal behaviour, neuroanatomy, and brain development. The ‘control-of-input’ model is then taken to a group and societal level to explain research findings and lay out new hypotheses within sociology, human-computer interaction, and linguistics. A multitude of applications of PCT have developed over the decades – the book’s authors have contributed their research on Method of Levels – a face-to-face psychological therapy based on PCT, on organisational and work psychology, and on robotics. I round off the book with a chapter to examine the pathway of PCT to mainstream science, suggesting the focus of future research and development of the theory.

So is our book all you need to know on a world-leading interdisciplinary theory of behaviour? The answer is an emphatic ‘No’ – not because it isn’t illuminating, accessible, detailed and comprehensive. We have had some wonderful endorsements to suggest this is the case:

“Constantly thought-provoking, thoroughly recommended”

Prof Pasco Fearon

“An exciting book on a simple but very powerful theoretical idea”

Prof Wilfried Kunde

“This collection is a tremendous contribution to the literature.”

Prof Tim Dalgleish

“Revolutionary work” Prof Tom Scholte

“A marvellous book” Prof Louise Barrett

“PCT is a fascinating, complex & profoundly fertile understanding of human being that combines scientific rigour with a deeply humanistic ethos” Prof Mick Cooper

Rather, if you begin with the Handbook, you can start on an incredible journey to learn more – about the theory itself – and about the increasingly broad range of disciplines it covers. To take a few examples, these include coping with cancer, theatre and film, public health, pharmacy, education, building design, and philosophy. Every one of these areas bristles me with excitement as they develop at the moment. Maybe this is because, like Powers, I can imagine how a theory that provides a collective vision to the many specialisms within our increasingly professionalised world, has the capacity to bring us all together for effective projects in the future to address society’s needs more efficiently and effectively. Or maybe they are just interesting in themselves…

Whichever it is, bring on the 21^st century renaissance!

About the book

• Presents case studies that show how PCT can be applied in different disciplines
• Illustrates the Test for the Controlled Variable (TCV) and the construction of functional models as fruitful alternatives to mainstream experimental design when studying behavior
• Shows how theory illuminates structure and functions in brain anatomy
• Compares and contrasts PCT with other contemporary, interdisciplinary theories

The Interdisciplinary Handbook of Perceptual Control Theory is available now to purchase on the Elsevier store. Enter STC320 at the checkout to save up to 30%