decline in illnesses such as pneumonia and influenza. He showed, however, that the
reduction in such illnesses was already underway before the development of the relevant
medical interventions. This is illustrated in Figure 2.1 for tuberculosis.
McKeown therefore claimed that the decline in infectious diseases seen throughout
the past three centuries is best understood not in terms of medical intervention, but in
terms of social and environmental factors. He argued that:
The influences which led to [the] predominance [of infectious diseases] from the time of the first
agricultural revolution 10,000 years ago were insufficient food, environmental hazards and
excessive numbers and the measures which led to their decline from the time of the modern
Agricultural and Industrial revolutions were predictably improved nutrition, better hygiene and
contraception.
(McKeown 1979: 117)The role of behaviour
McKeown also examined health and illness throughout the twentieth century. He argued
that contemporary illness is caused by ‘influences... which the individual determines by
his own behaviour (smoking, eating, exercise, and the like)’ (McKeown 1979: 118) and
claimed that ‘it is on modification of personal habits such as smoking and sedentary
living that health primarily depends’ (McKeown 1979: 124). To support this thesis,
McKeown examined the main causes of death in affluent societies and observed that
most dominant illnesses, such as lung cancer, coronary heart disease, cirrhosis of the
liver, are caused by behaviours.
Behaviour and mortality
It has been suggested that 50 per cent of mortality from the ten leading causes of death
is due to behaviour. This indicates that behaviour and lifestyle have a potentially major
Fig. 2-1 Decline in mortality from tuberculosis (after McKeown 1979)HEALTH BELIEFS 15