xv, 103 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / The purpose of the current study was to examine the role of sociocultural factors in posttraumatic stress. The two major aims were to add to current knowledge about why women report higher rates of posttraumatic stress than men and to explore the role of ethnicity in response to trauma. Using an online survey with a college sample (n = 1041) and a community sample (n = 199), the findings confirmed prior research that traumas high in betrayal (e.g., abuse by a close other) are more strongly associated with symptoms of posttraumatic stress than traumas lower in betrayal (e.g., natural disaster or abuse by someone not close to the victim). Women also reported higher rates of depression, anxiety, and reexperiencing symptoms of posttraumatic stress disorder (PTSD) but not avoidance and hyperarousal symptoms. The hypothesis that betrayal trauma would mediate the association between gender and PTSD reexperiencing symptoms was statistically significant although the effect was not substantial. Gender role socialization may also moderate the relationship between gender and PTSD reexperiencing, whereby men with more egalitarian beliefs had lower scores than men with more conservative beliefs. This study also investigated the rates of traumatic events among Asian and Pacific Islander (API) populations, and cultural correlates of posttraumatic stress. It included one of the few non-clinical samples of API adults from the community in the U.S. as well as a cohort of API students. Notable differences between the younger and older API participants were found in the reporting of various traumatic events. In particular, young API men reported adult sexual assault with surprising frequency at nearly 20% for both close and not close perpetrators which is several times more than the older API men. The influence of participants' concern with loss of face (LOF) on PTSD symptoms was also examined. The prediction that concern with LOF would moderate the effect of traumatic experiences on posttraumatic stress for APIs was not supported although LOF was directly associated with PTSD symptoms. These results add to the growing body of evidence that interpersonal violence and posttraumatic stress are issues that require attention among API populations. / Committee in charge: Jennifer Freyd, Co-Chairperson, Psychology; Sanjay Srivastava, Co-Chairperson, Psychology; Jeffrey Measelle, Member, Psychology; Jocelyn Hollander, Outside Member, Sociology