His childhood experiences of Glasgow's slums informed his later work, and led to his membership of the Labour Party which he joined at the age 16, and only left when in his nineties in his disgust at the Second Gulf War.
By performing a large scale survey, he first noticed in 1949 that the sedentary drivers of London's double-decker buses had higher rates of cardiovascular disease than the conductors who climbed the stairs.
[7] He extended the study and noticed that postmen who delivered the mail by bike or on foot had fewer heart attacks than sedentary men who served behind counters or as telephonists and clerks.
After several more years of study, he published the seminal paper on the topic in the British Medical Journal in 1958, titled Coronary Heart Disease and Physical Activity of Work.
In 1948 Horace Joules invited him to base the Medical Research Council's Social Medicine Unit at the Central Middlesex Hospital, where it went on to undertake seminal studies on infant mortality and the role of physical exercise in heart disease.
[11] His association with social scientists Richard Titmuss and Brian Abel-Smith, both at the London School of Economics (LSE), influenced health policy development under the UK's Labour governments of the 1960s.
A record of this event, with presentations by Michael Marmot, Roger Bannister and other experts, was published in association with the proceedings of a conference on Epidemiology, Social Medicine and Public Health.