Being top of the pile has its advantages, you have more power, things are more likely to be done your way, but it comes at a price - your stress-hormone levels are likely to be considerably higher than others, Princeton University ecologists wrote in the journal Science. Although this study observed baboon hierarchy, most likely being the alpha male means suffering higher levels of stress for most animals, including humans.
The authors found that within wild baboon populations, the top ones, termed alpha males had much higher stress-hormone levels than the beta males; the ones directly below them. Even during periods of relative peace and stability, they were still in a higher state of stress.
The scientists say their findings will interest those who study human and other animal populations, now knowing that social dominance is a factor that can affect health and well-being.
Lead author Laurence Gesquiere, said:
"An important insight from our study is that the top position in some animal - and possibly human - societies has unique costs and benefits associated with it, ones that may persist both when social orders experience some major perturbations as well as when they are stable. Baboons are not only genetically closely related to humans, but like humans they live in highly complex societies."
The researchers examined 125 adult male baboons from five social groups, all living in the wild in the Kenyan Amboseli Basin. They had gathered data from the Altmann research group, which included their life histories and behaviors over a 40-year period.
Over a nine-year period the scientists collected fecal samples and tested them for levels of glucocorticoid and testosterone; both of them stress hormones.
The authors say their study is five to ten times greater in data content compared to any other study on any non-human primate group. Gesquiere explained that the sheer volume of their data allowed them to control for key variables that may have affected stress hormones.
Co-author, Susan Alberts explained that the study's long duration and large size meant they could evaluate the long term-effects of maintaning rank in general, rather than having to focus on a small number of 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."
The authors stressed that the alpha males' higher hormone stress levels more likely were for the amount of energy they had to use up making sure they stayed on top, instead of any psychological factors.
A typical alpha male spends much more of his time fighting and keeping others away from his mate than beta males do.
The researchers wrote:
"They do not differ, however, in the rate of challenges to their status, which is considered a psychological stressor, or in the amount of grooming they receive from adult and juvenile females, which is a measure of psychological support.
Baboons are likely to be good models to provide insights for identifying the ideal position in a complex society under different conditions," Altmann said of the study's potential insights into research on human behavior. "Humans also live in stratified societies, and social status is well known to be associated with some but not all health outcomes in humans.
It has been difficult to identify many of the mechanisms behind these associations," she added. "Our results point to the need for research that will identify and evaluate the specific costs and benefits of various status positions, in various species, types of organizations and groups, and under different ecological conditions."
"Life at the Top: Rank and Stress in Wild Male Baboons"
Laurence R. Gesquiere, Niki H. Learn, M. Carolina M. Simao, Patrick O. Onyango, Susan C. Alberts, Jeanne Altman
Science 15 July 2011: Vol. 333 no. 6040 pp. 357-360 DOI: 10.1126/science.1207120
Written by Christian Nordqvist