This application seeks funding for an International Scientific Research Development Award (IRSDA), with the focus on economics, demography, and the social and biological aspects of human development at the University of California at Berkeley and the Mexican National Institute of Public Health (INSP) in Cuernavaca, Mexico. The candidate, Lia C. Fernald, is currently a Post-Doctoral Fellow in the Institute for Business and Economic Research at UC Berkeley, and previously received a Ph.D. in Clinical Medicine and an M.B.A. with a focus on Health Care Management. The IRSDA will allow the candidate to have a period of mentored research that will prepare her to pursue a successful independent research career in international public health. The candidate' s long-term goal is to use high quality evaluation and research as a tool to develop effective and sustainable programs that promote positive social change in developing countries. She aims to develop a base of skills and knowledge that are critical to conducting research and interventions in large scale, community-based, poverty- alleviation programs. Her goals are I) to gain expertise in the theory and methodology of economics and demography; 2) to gain expertise in advanced quantitative methods for analyzing multi-level, complex, longitudinal public health and economic data; 3) to develop an understanding of health psychology and human development in relation to socioeconomic status (SES); and 4) to apply this knowledge of demographic and econometric models, and human development to the development of socio-economic metrics and analysis of health outcomes. She plans to achieve these goals through a combination of direct coursework, one-on-one tutorials, and a mentored research project. Based primarily on animal work, some researchers suspect that activity of stress-sensitive physiological systems may mediate associations between SES and both health and behavioral outcomes. Although investigators are beginning to examine concurrent relations between physiological stress responsivity and SES, no studies with humans have been able to directly address the issue of causality directly. Dr. Fernald will ask the critical question whether an improvement in socio-economic status can effect change in basal and regulatory aspects of stress physiology. She will take advantage of a large, randomized, controlled-trial of poverty reduction in Mexico (the PROGRESA program) to investigate the impact of a poverty-alleviation program on activity of physiological stress in children. She will also use the experimental model to begin to identify factors mediating the impact of PROGRESA on stress reactivity.