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diet had changed, perhaps reflecting stress due to a greater reliance on cash crop-


ping (Yazawa et al. 2014 ). Conversely, cell phone use among the Hainan Islanders


was associated with a decrease in EBV antibodies, reflecting greater modernization


but also enhanced ability to tap into social networks, and thus greater social support.


Social support is usually viewed as a stress buffering factor (Sarason et al. 1985 );


social relationships that provide support change with modernization, but these


social relationships entail both support and obligations to provide support for


others. Among Samoan women undergoing social change, immigrants with larger


social support as measured by involvement in community associations actually


showed higher levels of stress, as measured by epinephrine excretion rates, than


those with smaller networks, while in Samoa and American Samoa the reverse was


true: greater community involvement was associated with lower epinephrine


excretion (Hanna 1998 ). Apparently the greater community involvement was


stressful to the immigrants because it entailed greater social obligations which were


generally stressful, while the support provided by involvement in community


associations buffered stress in the non-migrants.


Migrants are also exposed to very rapid culture change. In a study of young male


Afghan immigrants to Denmark, blood pressure and plasma norepinephrine levels


were higher in the immigrants than in native Danes (Asmar et al. 2013 ). There are


individual differences in the response to migration, including sex differences. For
instance, among Russian immigrants to the USA, increased mastery of the new


culture was associated with an average lowered cortisol level in men, but increased


cortisol levels in women (Nicholson et al. 2013 ). Filipino American immigrants to


Hawaii with intermediate levels of“Americanization”had significantly elevated


norepinephrine levels than immigrants with high or low levels of Americanization


(Brown 1981 , 1982 ), and immigrant Filipino American nurses and nurse’s aides


who had lived in the U.S. for a longer time period had higher norepinephrine


excretion rates during waking hours, and higher ambulatory diastolic blood pressure


during sleep, than more recent immigrants (Brown and James 2000 ). Differences in


stress levels between migrants and those who do not migrate are not just due to


stress; there are situation-specific conditions that may lead to selective migration in


which those who migrate have different characteristics than those who choose not to


migrate (Pearson and Hanna 1989 ). In general, however, increased norepinephrine


levels are found in people living in modernized environments, whether they have


migrated or not (Pearson and Hanna 1989 ; Hanna et al. 1991 ; Pearson et al. 1993 ).


Summary


People differ widely in what stimuli they consider to be stressful, and the appraisals


of threat and difficulty in coping are sometimes not conscious ones. Self-reports of


stress therefore do not capture all conditions in which people are under stress, and


individuals also differ in when it is appropriate to report that they believe they are
under stress. If stress responses can occur without being conscious of them, then


7 Stress Biomarkers as an Objective Window on Experience 133

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