The purpose of the proposed research is to examine the degree to which a variety of environmental challenges evoke autonomic nervous system (ANS) arousal in subjects possessing the Type A coronary-prone behavior pattern. Specifically, noninvasive cardiovascular indices of ANS arousal will be recorded while Type A and Type B (noncoronary-prone) subjects are subjected to a variety of carefully controlled conditions which have differential social salience and/or performance requirements to determine which conditions produce the most robust physiologic activation. Both healthy male college students and working adults will be studied to explore reactions that are possibly influenced by age differences. Specific components which comprise the Type A pattern will be assessed using the structured interview to determine whether some components are more predictive of ANS arousal than others and whether these comoponents are the same ones found to be predictive of coronary heart disease (CHD). Finally, a new instrument specifically designed to assess components of the Type A pattern most predictive of CHD will be examined with regard to its ability to agree with traditional measures of the Type A pattern and to predict ANS arousal in Type A and B subjects. The proposed research has implications for further refinements in the definition of coronary-prone behavior and its possible relationship to CHD, in procedures for assessing coronary-prone behavior, in the identification of the physiologic correlates of coronary-prone behavior, and, ultimately, in the modification of coronary-prone behavior.