Date of Graduation


Document Type


Degree Type



Eberly College of Arts and Sciences



Committee Chair

Kevin T Larkin

Committee Co-Chair

Amy Fiske

Committee Member

Stephanie Frisbee

Committee Member

Daniel McNeil

Committee Member

Nicholas Turiano


Studies examining the association between dispositional optimism and autonomic reactivity to stress have yielded mixed results, with some studies finding associations between optimism and less reactivity, some studies finding no association between optimism and reactivity, and some finding that optimism was associated with greater reactivity. One factor not considered previously in this literature is difficulty of the stressful task employed to elicit autonomic reactivity. The current study was based on Carver and Scheier's Behavioral Self-Regulation Model (Carver & Scheier, 2000), that states that optimists are more likely to persist in overcoming challenging obstacles than pessimists. The current study investigated whether the relation between optimism and autonomic reactivity to stress differed depending on the difficulty of the stressful task. This study employed a quasi-experimental design in which participants were classified as optimists or pessimists based on their score on a validated measure of optimism. Participants were randomized to complete either an easy Raven's Matrices stress task or a difficult Raven's Matrices stress task. Blood pressure (systolic, diastolic, mean arterial), heart rate, and heart rate variability were measured throughout the pre-task rest period, the task period, and a recovery period. It was hypothesized that optimists would exhibit increased cardiovascular reactivity when confronting a difficult stress task compared to pessimists, due to fully engaging their resources to overcome the task. Conversely, pessimists were hypothesized to exhibit less cardiovascular reactivity during the difficult task, because they were not fully engaged in solving the problems. No differences in cardiovascular reactivity between optimists and pessimists were hypothesized during the easy task, because both groups would be equally engaged with the task.;Results revealed that optimists had greater diastolic blood pressure reactivity to both the easy and difficult stress tasks compared to pessimists, suggesting they may have been more engaged with the tasks compared to pessimists. Indeed, optimists reported being more persistent in completing the problems and performing better on them compared to pessimists. Analysis of affective responses to the tasks showed that optimists reported more positive affect and less negative affect than pessimists during the laboratory session. However, there were no differences between optimists and pessimists on task performance, ratings of task self-efficacy, and ratings of task difficulty, stressfulness, discomfort, or perceived effort. Significant task effects were revealed as well, verifying that the easy and difficult tasks were experienced differently. Participants completing the difficult task performed more poorly, reported less positive and more negative affect in response to the task, and rated the task as more difficult, stressful, effortful, and upsetting than participants completing the easy task. Although results of the study failed to confirm study hypotheses, they added credence to the Behavioral Self-Regulation Model because optimists appeared to be engaging more with both easy and difficult versions of the stress task than pessimists, and consequently, experienced greater DBP reactions during the task period than pessimists.