Last nights argument could do more than make you glare at each other over breakfast. Bickering raises stress so much that it delays your body's ability to heal, say husband and wife researchers Ronald Glaser and Janice Kiecolt-Glaser at Ohio State University. They inflicted 42 couples with blisters. At the first visit, the twosomes discussed topics that encouraged support from each other; next time, they were asked to resolved a disagreement. After each session, the Glasers took samples of the blisters and measured levels of cytokines, messenges that summon healing cells to the wound. Cytokines were lower after the conflicts than after the supportive talks, and the most hostile pairs took two days longer to heal, on average, than the least hostile.