In societies that have a hierarchical structure, being at the top of the hierarchy has significant advantages. High ranking individuals in hierarchical societies usually have the best lifestyles. Field biologists have coined the terms alpha and beta males for individuals at the top of societies that are established among chimpanzees, gorillas, wolves, lions, and baboons. The alpha male in a baboon troop can have his pick of the best food and most fertile females, and his offspring usually are more healthy and stronger. Researchers from Princeton University, lead by Dr. Laurence Gesquiere, have shown that being the alpha male in a baboon troop has significant impacts upon male and stress hormone levels. Their research was published online in the journal Science. The researchers studied a troop of baboons in their natural habitat over a long period of time. Hormone levels for testosterone and glucocorticoids were tested in the alpha male, beta males and other lower ranking males. Testosterone is a male hormone and regulates many male physiological processes such as sperm production, muscle mass production, male secondary sexual characteristics, and sexual and aggressive behaviors. Glucocorticoids are hormones that are involved in regulating stress and are usually elevated in dangerous and stress inducing situations. The researchers found that the beta males had very high levels of testosterone but lower levels of glucocorticoid hormones. The lowest ranking males had lower testosterone levels but higher glucocorticoid levels, presumable because they needed to defend themselves from other males. The one exception to this rule was that the alpha male had very high testosterone levels and very high glucocorticoid levels. Of particular interest was the fact that alpha males had significantly higher levels of stress or glucocorticoid hormone levels. The authors wrote, “alpha males exhibited much higher stress hormone levels than second-ranking (beta) males, suggesting that being at the very top may be more costly than previously thought”. These findings suggest that being at the very top, or being the alpha male, has significant advantages but involves much higher stress levels and a greater expenditure of energy. Taken all together, these results suggest that being second in rank may be less stressful from a hormonal perspective, but still be as rewarding.
Laurence R. Gesquiere et al. “Life at the Top: Rank and Stress in Wild Male Baboons” Science 333, 357 (2011); DOI: 10.1126/science.1207120