With no more room left on Earth, and with Mars hanging up there empty of life, somebody hit on the plan of starting a colony on the Red Planet. It meant changing the habits and physical structure of the immigrants, but that worked out fine. In fact, every possible factor was covered--except one of the flaws of human nature....
Two Timer in the February 1954 issue of Galaxy Science Fiction. Here is a brace of vignettes by the Old Vignette Master. short and sharp. like a hypodermic! - Experiment - Sentry