A number of social cognition models have been developed to account for soci
o-demographic variations in health behaviour. This paper distinguishes betw
een: (a) motivational, (b) behavioural enaction, and (c) multi-stage models
of health behaviour. The models are evaluated in terms of advancement of e
xisting knowledge and - where appropriate - predictive utility. Common them
es that appear within- and between- these categories are discussed, with co
nsideration of ways in which theory may be advanced by future research. Eac
h approach has associated strengths and weaknesses, suggesting that a "cons
ensus" approach to the study of health behaviour may prove fruitful. Identi
fication of the key constructs across different model types would allow coh
erent integration and promote further understanding of the psyche-social de
terminants of health behaviour.