Alpha males may pay a price for their dominance in society, suffering more stress than others, a U.S. study says. Researchers at Princeton University said findings in studies of baboons that suggest maintaining a dominant position in a social hierarchy causes stress levels to increase could also be applied to human societies. "Baboons are not only genetically closely related to humans, but like humans they live in highly complex societies," researcher Laurence Gesquiere said. The study involved 125 male baboons from five social groups in Kenya that measured levels of the stress hormones glucocorticoid and testosterone, The Daily Telegraph reported Friday. Stress is probably the result of the energy needed by alpha males to maintain their superior social position rather than psychological factors, the researchers said, with alpha males more likely to fight than beta males. "We've known for decades that alpha males have an advantage in reproduction, but these results show that life at the top has a real downside, and that being an alpha male comes at a real cost," researcher Susan Alberts said. "Humans also live in stratified societies, and social status is well known to be associated with some but not all health outcomes in humans," study leader Jeanne Altmann said.