The Type A behavior pattern as described by Friedman and Rosenman is characterized by extremes of competitiveness, easily aroused hostility, a sense of urgency and aggression. In 1981 the Review Panel of Coronary Prone Behavior and Coronary Heart Disease concluded that the Type A behavior pattern was associated with an increased risk for coronary heart disease. Studies have challenged the independent predictive value of the behavior pattern with respect to coronary heart disease. There was a need to develop physiological measurements related to coronary-prone behavior and to reexamine the stability of the psychological assessment. It was hypothesized that Type A behavior or some component such as hostility might be associated with a state of chronic, generalized sympathetic-adrenal arousal. Preliminary research was conducted on interpersonal dynamic correlates of Type A behavior among married couples. Research was needed on whether certain types of marriages, according to the Type A/B classification of the two spouses, are more pathogenic than others. Additional research is also needed on which components of the global Type A pattern were of primary importance as risk factors for coronary disease, and which components were enduring, which were transient, and which were situationally related.