Men worked harder to earn money for charity when someone was watching them, unless they had been given testosterone. In a University of Vienna study of 192 men, a single dose of the hormone wiped out that watched-by-others boost in generosity. Each man rubbed a gel onto his upper arms and shoulders. For half of them it held 150 milligrams of testosterone, and for the rest it was an identical gel with none, and neither the men nor the researchers knew who got which. The men then played a learning game, working out which symbols paid off, sometimes to win money for themselves and sometimes for a charity they picked. Neuropsychopharmacology published the study in 2023. Some men played while two women, introduced as charity representatives, sat in the room watching. The rest played alone. They were told nobody would ever see their results. Men on the plain gel made more correct choices for the charity when they were being watched. Men on testosterone chose the same way whether anyone was watching or not. The hormone left their ability to learn the game intact, and when they were watched, it changed how closely their choices followed what they had learned. Among men on the plain gel, those who cared most about conformity and tradition were the most consistent when watched. Testosterone erased that link. The authors describe the extra generosity in front of an audience as strategic, a way of looking good, and say testosterone pushed against that kind of conformity. This was one dose, a lab game, and healthy men aged 18 to 40. For these men, testosterone removed the extra effort that only appeared when someone was watching.