Dr. Holmes is currently investigating social hierarchies and health disparities in the context of US-Mexico migration and the ways in which these inequalities become understood to be natural and normal. This project draws on approximately eighteen months of full-time participant-observation, during which time Dr. Holmes migrated with undocumented indigenous Mexicans in the United States and Mexico, picked berries and lived in a labor camp in Washington State, pruned vineyards in central California, harvested corn in the mountains of Oaxaca, accompanied migrant laborers on clinic visits, and trekked across the border desert into Arizona. An article from this work has been awarded the Rudolf Virchow Award from the Society for Medical Anthropology. Concurrently, he is conducting research into the processes through which medical trainees learn to perceive and respond to social difference. In addition, Dr. Holmes is exploring new interdisciplinary research into the social, cultural, and political processes producing high HIV death rates among specific groups of people, notably Latino day laborers and other ethnoracial minorities, homeless people, and sexual minorities. This new project addresses the ways in which political economic structures and social categories affect individual behavior and vulnerability.