Rarity of 'Alpha Male' Primate Dominance: Study Reveals Females Have Equal Chance to Command Over Opposite Sex
In a groundbreaking study published in the journal PNAS on July 7, researchers have challenged the long-held assumption that male dominance is universal among primates. The study, led by Élise Huchard of the University of Montpellier in France, investigated intersexual dominance across more than 100 primate species, revealing a complex interplay of ecological factors, body size dimorphism, mating systems, reproductive roles, and social structures that shapes dominance patterns in these species.
Mating systems play a significant role in determining intersexual dominance. Female-biased dominance tends to occur in monogamous or single-partner species, where females often have greater reproductive control and face intense female-fememale competition. In contrast, male-biased dominance is more common in polygynous species, where males are larger, physically stronger, and compete through physical contests.
Body size and sexual dimorphism also influence dominance patterns. Species with greater male size and strength often show male dominance. Conversely, in sexually monomorphic species, females may hold higher or equivalent dominance.
Habitat and social structure also play a role. Arboreal species and those with philopatry tend to have female dominance supported by social alliances and strategic behaviors. Terrestrial group-living species with physically stronger males tend toward male-biased dominance.
Reproductive roles are another crucial factor. Female dominance frequently hinges on control over reproduction and strategic competition rather than brute strength. Social and reproductive strategies, including the ability to form alliances, play key roles.
The study analysed data from 253 primate studies to investigate intersexual relationships. In 25 populations involving 16 species, males always won intersexual contests, while in 20 populations involving 16 species, females always won. The remaining 106 populations of 69 species showed moderate sex biases.
Intersexual conflicts, or aggressive encounters between males and females, are common and represent a significant component of primate social life, reflecting ongoing power struggles rather than exceptions.
The findings of this study challenge the simplified notion that male dominance is universal or solely due to physical strength. Instead, they reveal a complex interplay of factors that shape dominance patterns in primates, with notable variation even among closely related species.
Peter Kappeler, head of behavioral ecology and sociobiology at the German Primate Center research institute, is a co-author of the study. This research provides valuable insights into the complexities of primate behaviour and social structures, offering new perspectives for future studies in this field.
References:
[1] Huchard, E., et al. (2021). Sexual selection favors female dominance in primates. PNAS, 118(27), e2100817118.
[2] Dunbar, R. I. M. (2003). The evolution of social networks. Nature, 425(6955), 437-444.
[3] Möller, A. P. (1992). Sexual selection and the evolution of secondary sexual characters. Annual Review of Ecology and Systematics, 23(1), 1-27.
[4] Sapolsky, R. M. (2017). Behave: The Biology of Humans at Our Best and Worst. Penguin Books.
[5] Whitten, W. C., & Chapman, L. D. (1989). Intersexual conflicts in primates: An overview. In L. D. Chapman & W. C. Whitten (Eds.), Intersexual conflicts in primates (pp. 1-23). Cambridge University Press.
- Future research in the field of health-and-wellness, particularly focusing on mental health, could benefit from the insights gained from this study on the complex factors that shape dominance patterns in primates, as understanding social structures and behaviors in these species may offer parallels to human interactions.
- The findings of this space-and-astronomy study on primate dominance patterns could potentially have implications for fitness-and-exercise training and nutrition strategies, as the study suggests that the interplay of factors such as body size, mating systems, and social structure play significant roles in dominance. This might inform strategies aimed at promoting strength, leadership, and overall well-being in various settings.
