John Bowlby's first scientific papers express a viewpoint of the etiology of childhood disorders that gradually developed during his university years and the first years of his professional life. As becomes clear from, among other things, Bowlby's private correspondence, it was the period spent as a student at Cambridge, his work as a teacher at two progressive schools, and his work at a child guidance clinic that allowed him to articulate a view on childhood deviancy that was at variance with the Kleinian variant of psychoanalysis. Bowlby's position as an 'independent' thinker in the British Psycho-Analytical Society can be understood against the background of these intellectual influences.