Although he left school at the age of 12, like many of the union leaders of those days he was an autodidact who studied electrical theory, economics and accountancy, as well as learning the relatively ornamental Gregg shorthand writing – a skill that stood him in good stead as a union official. As a member of the Independent Labour Party from 1906, he became widely read in the standard socialist tracts, including Marx's works and from the 1910s Citrine was quite left-wing with mildly-syndicalist views.