The vastness of the universe (i.e., cosmic vastness) can evoke polarizing existential experiences. Some people report elevating experience, such as awe, elevation, and self-transcendence, whereas others experience existential distress, such as feeling insignificant, powerless, and vulnerable. The purpose of this thesis was to examine three main research questions: 1) How do people react to the vastness of the universe? 2) What is it about witnessing cosmic vastness (i.e., mediators) that elicits polarizing experiences? 3) What is it about a person and their individual traits (i.e., moderators) that causes people to react differently? Two studies were conducted to investigate these questions. Study 1 was a primarily qualitative in-lab study where participants watched one of two videos depicting the vastness of the universe. Participants answered open-ended questions about their experiences, along with some preliminary quantitative questions, and these responses were used to inform what experiences were measured in Study 2. Study 2 was an online quantitative experiment in which a cosmic vastness video was compared to two other videos (Earth nature vastness and neutral control). Study 2 also examined mediators and moderators that explain the relationship between witnessing cosmic vastness and both elevating experience and existential distress. Both studies found that facing cosmic vastness can elicit positive and negative experiences. Study 1 found that most participants reported positive (93%) and negative experiences (68%), including a substantial degree of elevating experience (58%) and existential distress (46%). Study 1 also found several cognitive responses that were good candidates to be mediators in Study 2, including small self, need for accommodation, experience of the unknown, and existential contemplation. Study 2 showed that a cosmic vastness condition elicited greater levels of elevating experience than the neutral control condition and greater levels of existential distress than both the neutral control and Earth nature vastness conditions. Results from both studies also found significant polarization in participants responses, such that half of the participants reported more elevating experience, and half of participants reported more existential distress. Mediation analyses in Study 2 demonstrated that the four cognitive responses each mediated the positive relationship between witnessing cosmic vastness and both elevating experience and existential distress. Furthermore, moderation analyses revealed that self-esteem moderated the relationship between witnessing cosmic vastness and elevating experience, whereas both self-esteem and meaning in life moderated the relationship between cosmic vastness and existential distress. This research provided unique contributions to literature on how people react to vast stimuli that has the capacity to be existentially threatening. Further implications of these results are discussed, as well as how these results may generalize to other areas of research.

Purpose: The Demoralization scale (DS-I) is a validated and frequently used instrument to assess existential distress in patients with cancer and other severe medical illness. The purpose of this study was to provide normative values derived from a representative German general population sample and to analyze the correlational structure of the DS-I. Methods: A representative sample of the adult German general population completed the DS-I (24 Items), the Emotion Thermometers (ET) measuring distress, anxiety, depression, anger, need for help, and the Functional Assessment of Chronic Illness Therapy Fatigue Scale (FACIT-fatigue). Results: The sample consists of N = 2,407 adults (mean age = 49.8; range = 18–94 years), 55.7% women). The percentages of participants above the DS-I cutoff (30) was 13.5%. The mean scores of the DS-I dimensions were as follows: (1) loss of meaning and purpose: M = 2.78 SD = 4.49; (2) disheartenment: M = 3.19 SD = 4.03; (3) dysphoria M = 4.51 SD = 3.20; (4) sense of failure: M = 6.24 SD = 3.40; and for the DS-I total score: M = 16.72 SD = 12.74. Women reported significantly higher levels of demoralization than men, with effect sizes between d = 0.09 (Loss of Meaning) and d = 0.21 (Dysphoria). Age was not associated with demoralization in our sample. DS-I reliability was excellent (a = 0.94) and DS-I subscales were interrelated (r between 0.31 and 0.87) and significantly correlated with ET, especially depression, anxiety, and need for help and fatigue (r between 0.14 and 0.69). Conclusions: In order to use the DS-I as a screening tool in clinical practice and research the normative values are essential for comparing the symptom burden of groups of patients within the health care system to the general population. Age and sex differences between groups of patients can be accounted for using the presented normative scores of the DS-I.