In this paper, we developed a comprehensive health performance measure that formally links individual health attitudes with the likelihood of engaging in a wide variety of health-related behaviours from various domains such as sustenance, hygiene, and physical exercise. Within what Kaiser, Byrka, and Hartig (2010) call the Campbell paradigm, we equated general health attitude with what a person does to retain or promote his or her health. Thus, health behaviours, on one hand, were expected to form a homogeneous, transitively ordered class of behaviours. On the other hand, the very behavioural class was in turn thought to be the basis from which an individual's health attitude could be directly assessed. A sample of 391 adults provided us with survey data containing different sets of health behaviours as well as variables and personality measures that had been corroborated as health-behaviour relevant in previous research. We found that self-reports of 50 behaviours and expressions of appreciation for 20 of these behaviours from various domains formed a transitively ordered class of activities. In contrast to the conventional view in health psychology, in which attitudes are regarded as a psychological cause behind individual behaviour, and in contrast to conventional findings in health psychology, where behaviours appear to fall into numerous sets of more or less distinct domains of health-enhancing activities (e.g., exercising or avoiding risks), our findings speak of the psychological and formal unity of health behaviour. Inevitably, attitude measures grounded in the Campbell paradigm gauge individual attitudes, and just as much, they measure the health performance of individuals.