Social and physiological processes underlying sensation-seeking and behavioral inhibition: Potential mechanisms linking personality to health

• Main Author: Michael, Kerry C
• Format: Dissertation
• Language: English
• Published: Ann Arbor ProQuest Dissertations & Theses 2011
• Subjects: Anatomy & physiology; Behavioral psychology; Endocrinology; Health; Immunology; Personality psychology; Physiological psychology; Social psychology
• ISBN: 1124980350; 9781124980355

Sensation-seeking and behavioral inhibition are two behavioral traits that have distinct biological profiles as well as distinct mental and physical health outcomes. These behavioral traits and health outcomes are also influenced by life experiences. This dissertation explores the hormonal, immune, and social underpinnings of sensation-seeking and behavioral inhibition in humans and in rats, to provide insight into how these traits might contribute to certain health outcomes, specifically depression.
Chapter 1 is a broad overview of sensation-seeking, behavioral inhibition, and the biological and sociological contributors to these traits. Chapter 2 is a review of temperamental traits in animals and the utility of animal models to study the relationship between personality and immune function and health, which provides the basis for the animal-human comparisons made in the following chapters.
Chapter 3 describes a study based on an animal model, Sprague-Dawley rats, to investigate how innate and adaptive immune responses to antigen differ between exploratory versus inhibited rats. Results showed that inhibited animals had a greater innate response to lipopolysaccharide but a lower adaptive immune response as evidenced by lower delayed-type hypersensitivity in response to re-exposure to keyhole limpet hemocyanin. This evidence suggests a T H2 bias in the immune system of inhibited rats.
Chapter 4 examined the hormonal underpinnings of sensation-seeking in young women and assessed how these relationships were moderated by gender role identification. Results from this study showed that androstenedione, a hormone previously unexplored in regards to sensation-seeking, was associated with sensation-seeking in women. The direction of the association, however, was dependent on identification with gender role -- positive in women who identified as more masculine or with no gender role, and negative in women who identified as more feminine. There was no association in women who identified as both masculine and feminine.
Chapter 5 uses a similar method to Chapter 4, but added C-reactive protein as a marker of inflammation, and men were recruited as participants as well as women. These additions allowed for a comparison between men and women, as well as examining one of the major physiological factors involved with depression -- inflammation. Results showed that Thrill and Adventure Seeking was protective against depression in both men and women. Furthermore, CRP was associated with sensation-seeking, but again the direction of the association was dependent on gender role: positive in masculine women and negative in feminine women. Chapter 6 concludes the dissertation and discusses implications and suggestions for future research.