In the study, researchers from the Waseda and Kyushu Universities tested the mind-altering effects of an antibiotic called minocycline. Minocycline is a tetracycline antibiotic used to treat acne and other skin infections like MRSA and Lyme disease. The drug can also help with asthma symptoms. Past studies have shown that the drug can reduce symptoms associated with mental illness like schizophrenia and depression. Researcher stimulated 'honey traps', using eight photographs of attractive women, and got 98 male participants to rate how trustworthy they thought each of the women would be.

Researchers divided the men into two groups. The first group was given a four-day oral treatment course of minocycline and the second, control group, was given a placebo pill. The men were then asked to look at pictures of female faces and asked to choose how much of 1300 yen ($13) they were willing to give to each woman. Researchers explained that if the men chose to share the money, the amount would be tripled. However, the men were told that the females would get a choice to cooperate by sharing the money or betray by taking it all. The men were also asked to assess how trustworthy they thought each female was and how physically attractive she was. The men did not know that the women in the photographs had already decided, in advance, to either 'cooperate' or 'betray' the male players.