The thesis examined McMaster University undergraduates’ beliefs about health and contagion, and their implication for antibacterial soap use. A qualitative methodology was used and 30 participants were interviewed, and the transcripts coded and analysed for emergent themes. Students understand health in terms of having energy, being disease free, and as something to be achieved through healthy lifestyle choices and cleanliness. These beliefs form an explanatory model of health that has several key components used to make health decisions, including using or not using antibacterial soap. The participants see their health as continually threatened by sources of illness. Contagion is one of the principal threats identified and understood as transmitted through the air, or on the surfaces of contaminated people and objects. Two modes of defence were articulated in the interviews. Internal components of defence involve maintaining immune rigour; external components drives activities such as personal hygiene and cleaning to protect against pathogens. Men tend to have a more internally focussed explanatory model of health, while women have a more external focus. This seems to explain why the women in this study were eight times more likely to use antibacterial soap than the men, a finding that was statistically significant (p=.O27). Social values are expressed through the explanatory model, including social boundaries and morality. The model also aligns very well with the biomedical paradigm in that it reduces health to its physical components, provides a mechanistic explanation of the body, and separates mind and body as discrete entities and as an object of control. Biomedicine seems to be broadening into new social domains, such as gender, social boundaries and morality, which are also reflected in students' beliefs about health. / Thesis / Master of Arts (MA)