Collective Biologies is an engaging, theoretically astute, and crisply written ethnography of research participation and shifting notions of gender and modernity in Mexico. Emily A. Wentzell captures a sense of the way biomedical research increasingly becomes enfolded into the experiences and projects of everyday life and particular understandings and aspirations of modernity in a way that is both emergent and urgent to understand. Her thoughtful, accessible, and illuminating examination makes crucial contributions to scholarship in science studies, medical anthropology, and Latin American studies. - Megan Crowley-Matoka, author of (Domesticating Organ Transplant: Familial Sacrifice and National Aspiration in Mexico) Emily A. Wentzell's study challenges medicine's conception of the body as a discrete entity and the way medical testing is done and the results understood. It is an excellent contribution to both medical anthropology and to public health. - Laura A. Lewis, author of (Chocolate and Corn Flour: History, Race, and Place in the Making of "Black" Mexico) "This solid contribution to medical anthropology reifies the concept that individuals enfold themselves into larger, collective, societal arenas. Highly recommended. Lower- and upper-division undergraduates. Graduate students, faculty, and professionals." - G. R. Campbell (Choice) "Wentzells skill in describing these biological abstractions is impressive. She has the capacity to weave complex subjects together: class differences, Mexican gender norms, national stereotypes, history, the economy, racial stereotypes, sexual disease transmission, familial and educational concerns, perceptions of governmental function, and more." - William Sorensen (The Latin Americanist)