Journal of Health Psychology 18(1) 3 –9 © The Author(s) 2012 Reprints and permission:

hpq.sagepub.com Beliefs are a key concept in understanding health-related cognition and behaviour. The objective of this article is to offer some comments on the con-ceptualization of beliefs offered in the target arti-cle (Cromby, 2012), and to consider briefly some of the recent evidence demonstrating the close links between beliefs and affect, one of the key issues considered in the target article. As the target article rightly notes, belief is one of the core constructs that health psychologists need to work with to achieve desirable health outcomes. Rather optimistically, Cromby claims that ‘phi-losophy is where we usually turn when concep-tual clarity is required’. Unfortunately, as the article acknowledges, it turns out that there is very little agreement among philosophers about the meaning of this construct. In contrast, empiri-cally psychology has already done a great deal to define, operationalize and measure concepts such as belief in ways that are open to replication and verification. Within the field of experimental social psy-chology, we can look back on almost a hundred years of productive empirical work, and the development of well-accepted operational defini-tions of mental constructs such as belief, attitude Belief and affect: On the mental pre-cursors of health-related cognition and behaviou