BOSTON (AP) – Deborah Anderson had heard the urban legends about the contraceptive effectiveness of Coca-Cola products for years.

So she and her colleagues decided to put the soft drink to the test. In the lab, that is.

For discovering that, yes indeed, Coke was a spermicide, Anderson and her team are among this year’s winners of the Ig Nobel prize, the annual award given by the Annals of Improbable Research magazine to oddball but often surprisingly practical scientific achievements.

Anderson, a professor of obstetrics and gynecology at Boston University’s School of Medicine, and her colleagues found that not only was Coca-Cola a spermicide, but that Diet Coke worked best.

Duke University behavioral economist Dan Ariely won an Ig Nobel for his study that found more expensive fake medicines work better than cheaper fake medicines.

Ariely spent three years in a hospital after suffering third-degree burns over 70 percent of his body. He noticed some burn patients who woke in the night in extreme pain often went right back to sleep after being given a shot. A nurse confided to him the injections were often just saline solution.

People often think generic medicine is inferior, but gussy it up a bit, change the name, make it appear more expensive, and maybe it will work better, he said.

Geoffrey Miller, an associate professor of psychology at the University of New Mexico, and his colleagues knew of studies that found women are more attractive to men when at peak fertility. So they studied earnings of exotic dancers, to find they earned nearly double the money during shifts when they were fertile.