Marines drink more alcohol and are more sexually promiscuous than any of the other military branches. The RAND Corporation looked at thousands of active-duty service members and found Marines drink more than sailors, soldiers and airmen. In fact, they binge drink at rates nearly twice that of the Air Force. The data also showed that Marines are more likely to have multiple sex partners than other branches over the course of a year and less likely to use condoms. A sociologist who led the study said it likely has a lot to do with self-selection -- people who join the Marines often aren't the type of people who join the Air Force.