Alexander contends that there is ‘a primary control of the use of the self, which governs the working of all the mechanisms’ of the organism, and which, if consciously employed, allows for a control of human reaction, for an improvement in the sensory appreciation of the use of the organism which in turn is associated with an improvement in functioning throughout the organism. This primary control ‘depends upon a certain use of the head and neck in relation to the use of the rest of the body.’ The term ‘primary control’ is a shorthand phrase for a complex operation which needs substantial explanation.
In MSI Alexander uses the phrase ‘true primary movement’ (which is the movement which precedes other movements and which therefore provides the controlling factor in influencing subsequent movements). It can be regarded as the precursor for the term primary control.
Primary control first appears in a 1925 lecture:
The direction of the head and neck being of primary importance, he found, as I found, that if we get the right direction from this primary control, the control of the rest of the organism is a simple matter.
In this lecture Alexander refers to Magnus’ discovery of a central control, translated from the German ‘Zentralapparat’ which refers to centres (plural) in the brain stem. (See Magnus). ‘Primary control’ can therefore be seen Alexander as Alexander’s combination of ‘primary’ (from his own ‘primary movement’) and ‘control’ from Magnus’s ‘central control’. As Alexander for many years had referred to his technique as being one of ‘conscious control’, it is not difficult to see why the term ‘primary control’ would encapsulate an essential complex concept.
Alexander changed his description of ‘primary control’ between the 1932 and 1946 editions of UoS:
. . . in short, that to lengthen I must put my head forward and up.
As is shown by what follows, this proved to be the primary control of my use in all my activities.
Note that in the 1946 edition the above description of the primary control was changed to:
. . . in short, that to lengthen I must put my head forward and up.
The experiences which followed my awareness of this were forerunners of a recognition of that relativity in the use of the head, neck, and other parts which proved to be a primary control of the general use of the self.
Conflation with ‘central control’
The term ‘primary control’ is a shorthand phrase for an intricate and delicate psycho-physical attitude, and it was seized upon and used by many of Alexander’s followers. Already in the 1930s several of his doctor pupils would use the primary control in their letters and articles in medical journals.
Alexander, Dewey and several doctors who were pupils of Alexander initially assumed that central control was the physiological root of the primary control, leading them to use them interchangeably.
Alexander’s reference in The Use of the Self, 1932, laid himself open to criticism when he equated primary control with central control:
This primary control, called by the late Professor Magnus of Utrecht the ‘central control,’ . . .
This mistake was repeated in UCL. This in turn led people to think that there was a physical center in the brain for the primary control. The correction of this mistake only started with the South African Libel Case, where witnesses who were experts on physiology, repeatedly stated that Magnus’ discoveries did not apply to normal humans since the experiments were all carried out on decerebrate animals. Alexander clarified his concept in a letter to Frank Pierce Jones in 1945:
There really isn’t a primary control as such. It becomes a something in the sphere of relativity.
In a private letter in 1951 Alexander described the primary control as ‘a control that is primary in thought and action to all other forms of control.’
Walter Carrington, writing in 1950, differentiates between Alexander’s use of the term and Magnus’ definition:
Mr Alexander’s term ‘primary control’ describes something far more extensive than Magnus’ ‘central apparatus’, for it embraces all the postural activity of the organism, not only the ‘brain-stem’ mechanism but also the higher centres of the brain, and in particular, the cortical centres which Magnus did not investigate.
Dr. A. Murdoch described the primary control as a ‘master reflex’ in 1936:
If this be so then the very first movement in balancing takes place at the atlanto-occipital joint, and is the result of the sub-occipital muscles, so that this is the primary movement and is the primary control of all other movements of the body. It is the master reflex and conditions all other reflexes . . . 
This was repeated by Patrick Macdonald who also equates the primary control with a ‘master reflex’. The idea of primary control being synonymous with central control or being a master reflex has caused some people to think of the primary control as having a physical location (e.g. in the midbrain), i.e. reifying the primary control. This view is now obsolete. Jones wrote: ‘Alexander did not claim to have discovered an anatomical centre . . .’ See also Carrington in Explaining the Alexander Technique.
(The discussion as to whether the Alexander Technique facilitates or depends upon some reflex activity continues, see Scientific Explanations.)
Elsewhere, Patrick Macdonald writes:
‘Primary control’ is the name Alexander gave to the neck-head-back relationship, which determines the coordination of the rest of the body.
In most introductory writings to the Technique the primary control is described as a certain head-neck-back relationship. For example Westfeldt preferred to call it ‘HN & B pattern’ (head, neck and back pattern).
Carrington and Carey discuss the primary control in Explaining the Alexander Technique.
‘Head at the end of its tether – An analysis of primary control’ by John M. Wynhausen suggests that the ‘head forward and up’ happens by the action of the muscles sternocleido-mastoid and platysma. This view was subsequently severely contested in two letters, ‘Writers and the end of their tethers’ by Heather R. Kroll, Donald L. Weed, and ‘Writers and the end of their tethers’ by Kathleen J. Ballard.
Alex Maunder, in his Let Your Life Flow, holds the view that ‘The source of primary control is in the medulla oblongata, which is that part of the brain where the brain stem tapers off into the spinal column.’
‘What controls the primary control?’ by Richard Brennan; on exactly what the primary control is, how it works, and how to describe it.
There are a number of explanations of the primary control from an anatomical viewpoint; see Use of Anatomy and Physiology. See also discussions on head and neck.
Wilfred Barlow questions whether the primary control is as important as Alexander made out:
‘His [Alexander’s] concept of the ‘primary control’ seemed . . . to be saying that . . . our conscious regulation of this primary head-neck balance in some way was to become the single most important control in our lives – that in some way full self-realisation could depend on this factor, which would supremely regulate all of our functions . . . He himself did not make it clear why the full expression of our nature should be so dependent upon our having such a single control . . . None of this has been adequately worked out – it seems to me – either in Alexander’s writings or in what other people have written.’
Ron Dennis in his article, ‘Primary control and the crisis in Alexander Technique theory’, points to inconsistencies in teachers’ usage. In his ‘Defining primary control’ he suggests a definition of primary control: ‘. . . the process, as primary task, of bodily adjustment to gravity’.
A response to Ron Dennis’s criticism was: ‘Primary control – An essential component of Alexander’s theory’ by Colin Egan.
Chris Stevens argued that the use of the legs and feet influenced the head-neck-torso relationship so fundamentally that it is necessary start with the feet in order to maintain a free neck during activity.  (See Chris Stevens.)
In ‘Beyond posture’ Anthony Kingsley argues that the head-neck-back relationship is not primary, and hence is not a primary control. It is also argued in his introduction to the 2018 edition of UoS: ‘Despite Alexander’s notion of the primacy of the head, neck and back, no single element is actually primary.’
Primary control is central to the Alexander Technique, yet its exact definition is not clear, and it has caused debate and confusion.
Not all teachers today use the term ‘primary control’ in their everyday teaching (although it almost always features in all books on the Technique), but instead refer to the balance of the head on the top of the spine, or the head-neck-back relationship.