Do people become more optimistic about future adjustment to negative life events after rumination? Past research using a "top of the head" paradigm indicates that people estimate they would adjust more poorly for severe events and better for mild negative events than their peers. Selective focus (i.e., differential accessibility of information about assets and liabilities for coping) has been provided as an explanation for this effect, which is counter to research on "optimistic bias". Martin and Tesser's (1989) rumination model was applied to beliefs about one's comparative adjustment to negative life events. One hundred twenty undergraduate subjects were asked to imagine experiencing a Severe (HIV+) or Mild (Herpes) negative event at some future time, then to designate items on a reaction time task as either an Asset or Liability in coping with the event. The reaction time task and subsequent comparative adjustment ratings were made either immediately, after a delay that allowed for rumination, or after a delay without an opportunity for rumination. A thought-listing analysis of the audiotaped ruminations revealed that, as predicted, subjects became more optimistic over time. They initially discussed liabilities in coping with the Severe event but gradually considered assets. Comparative adjustment ratings for the Severe event were not significantly different than for the Mild event, even in the Rumination Absent condition. It was suggested that temporarily making assets for coping accessible through the reaction time task had the same effect on comparative adjustment ratings as did problem-solving through rumination. The reaction time data provided convergent evidence regarding selective focus and complimented a thought-listing paradigm used in previous studies. / Master of Science