# Kenneth Craik

Kenneth James William Craik (/kreɪk/; 1914 – 1945) was a Scottish philosopher and psychologist. A pioneer of cybernetics, he hypothesized that a human behaves basically as a servomechanism that controlled at discrete points in time. He influenced Warren McCulloch, who once recounted that Einstein considered The Nature of Explanation a great book.

## Life

He was born in Edinburgh on 29 March 1914, the son of James Bowstead Craik, an Edinburgh lawyer, and Marie Sylvia Craik (née Robson), a published novelist. The family lived at 13 Abercromby Place in Edinburgh's Second New Town (previously the home of William Trotter). He was educated at Edinburgh Academy then studied philosophy at the University of Edinburgh. He received his doctorate from Cambridge University in 1940. He then had a fellowship to St John's College, Cambridge in 1941, where he worked with Magdalen Dorothea Vernon and published papers with her about dark adaptation in 1941 and 1943. He was appointed to be the first director of the Medical Research Council's Cambridge-based Applied Psychology Unit in 1944.
During the Second World War he served in the fire-fighting sections of the Civil Defence. Together with Gordon Butler Iles he made major advances on flight simulators for the RAF and did major studies on the effects of fatigue on pilots.
He died at the age of 31 following an accident, where a car struck his bicycle on the Kings Parade in Cambridge on 7 May 1945. He died in hospital on the following day: VE Day. He is buried in the northern section of Dean Cemetery. His parents Marie Sylvia Craik and James Craik were later buried with him.
The Kenneth Craik Club (an interdisciplinary seminar series in the fields of sensory science and neurobiology) and the Craik-Marshall Building in Cambridge are named in tribute to Craik. The Kenneth Craik Research Award administered by St John's College was established in his memory in 1945.

## Works

In 1943 he wrote The Nature of Explanation. In this book he first laid the foundation for the concept of mental models, that the mind forms models of reality and uses them to predict similar future events. He is recognized as one of the pioneers of modern cognitive science.
In 1947 and 1948 his two-part paper on the "Theory of Human Operators in Control Systems" was published posthumously by the British Journal of Psychology. In in this paper, he argued that the human is an intermittent servomechanism performing serial ballistic control. In more detail, he hypothesized, based on multiple early experiments in human cognitive and motor control, that in motion planning, a human operates as a negative-feedback loop. The human continuously takes in sensory information, but does not continuously perform actions. Instead, once every ~0.5 seconds, the human selects an action. The selected action is then implemented by an open-loop controller that operate for ~0.2 seconds ("ballistic movement"). As the human learns, the motion performed by the open-loop controller becomes more refined, allowing the human system to approach an ideal continuous-time servomechanism.
current sensory information but then executed open-loop, i.e. without being influenced by feedback of the result. He demonstrated the refractory nature of tracking following an initial response to an unpredicted, discrete step stimulus and proposed the ubiquitous nature of serial ballistic control in humans at a rate of two to three actions per second
An anthology of Craik's writings, edited by Stephen L. Sherwood, was published in 1966 as The Nature of Psychology: A Selection of Papers, Essays and Other Writings by Kenneth J. W. Craik.