It's the hostility in type A personality that matters, but which element of hostility?

The links between personality and coronary heart disease have challenged investigators ever since Friedman and Rosenman first suggested that the disease was more common among people with a type A personality—time pressured, competitive, and aggressive.1 The research has tried to improve clinicians' ability to predict who is most vulnerable to coronary heart disease and so to identify people who are most likely to benefit from prevention measures. One result of this research was recently summarised in a meta-analysis by Miller et al which showed that hostility is an independent risk factor for coronary heart disease.2

Hostility is a broad concept. It has connotations of anger, aggression, and a chronic negative outlook and so encompasses feelings, overt actions, and thoughts or attitudes.3 The cognitive components (those involving thoughts and attitudes) may include cynicism or mistrust, a desire to oppose others, or a wish to do them harm.4 A distinction should be drawn between the experience of hostility and its expression.5 The experience of …