Observations of “alpha male” behaviour among apes – including some of humans’ closest relatives in the animal kingdom – have helped shape the archetype of the dominant male into a controversial touchstone of modern culture.

But a sweeping analysis of power dynamics between male and female primates confirms that the alpha male is relatively rare among 121 primate species, finding that sex-based hierarchies across the vast order are more fluid – and successfully contested more frequently – than was historically assumed.

The study’s authors say their research could pave the way to a deeper understanding into one of science’s murkiest questions: the origins of power inequalities between men and women.

“Male dominance is not a baseline, as was implicitly thought for a long time in primatology,” said Élise Huchard, a behavioral ecologist at the University of Montpellier who co-wrote the study. In a phone interview, she said that her research found there was far more flexibility in power dynamics between male and female primates than previously envisioned and that it raises questions over the extent to which modern inequities between men and women can be traced to humanity’s primate legacy.

The peer-reviewed paper, published Monday in the Proceedings of the National Academy of Sciences, reviewed quantitative data from 253 studies on contested interactions between male and female primates from 121 species.

The contested interactions included anything from acts of physical aggression to ritualized signals indicating submission.

The scientists recorded which sex “won” each interaction and then analyzed the data to compare the results between different species and populations of primates.

They found that for 70 percent of observed primate populations, neither sex was clearly dominant (defined as winning more than 9 in 10 contests.) At the same time, males were clearly dominant in 17 percent of populations and females in 13 percent.

“It’s actually a beautiful continuum, and most species lie in the middle and are not strictly male- or female-dominant,” Huchard said.

The study found that female power was most likely to arise in scenarios where females have the most choice in which partner to mate with. This includes species in which females are monogamous or where they are a similar size to males.

They also found that primate species that primarily forage in trees are more likely to be biased toward female power. “This is because it’s easier to escape, you’ve got three dimensions instead of two,” making it harder for males to wield control, Huchard explained.

It adds to a growing body of research into why males dominate in some primate species while females dominate in others. For example, a study in April found that female bonobos maintained power by forming alliances to gang up on males.

Research is showing that male-biased power is not as ubiquitous as once thought among primates, said Rebecca Lewis, a biological anthropologist at the University of Texas in Austin, who was not involved in Monday’s research paper.

“This study is part of a growing body of literature showing that when we think about power in animals as more than just who is biggest or baddest, when we recognize economic forms of power, such as the leverage that females derive from controlling reproduction, we find a wonderfully complex landscape of power,” she wrote in an email, describing the research as “an important step forward in our understanding of which selective pressures lead to inequality between the sexes.”

Nicholas Newton-Fisher, a primate behavioral ecologist at the University of Kent in England who also was not involved in the study, noted that the primate umbrella contains vastly divergent species and that grouping them together risks obscuring evolutionary differences.

He pointed to how the study found key differences between the branches: Where strict male dominance was more typical of apes and catarrhines (African and Asian monkeys), female dominance was typical of the strepsirrhines (lemurs and lorises), and sex-dominance was not clear-cut among the platyrrhines (South and Central American monkeys).

“It is worth noting that these three branches of the Primate have long and distinct evolutionary histories,” he wrote in an email, saying that differences in their biology are unsurprising.

The term “alpha male” entered the popular lexicon after appearing in a 1970 book on the ecology of wolves – a term that its author later lamented as incorrect and inaccurate when it came to the species. Subsequent research on wild wolves did not bear out the rigid, force-based dominance hierarchy helmed by an alpha that was observed among captive wolves.

Nevertheless, the term has crept into cultural discourse and even politics. Eric Trump has praised his father’s “alpha” personality, as many other MAGA supporters have embraced the term as a self-identifier to express their brand of masculinity.

Huchard said the paper’s authors found scant evidence to support the theory that sex-based inequities in humans originated from our primate relatives, pointing to the fact that humans share traits such as monogamy with groups of primates that don’t exhibit clear male dominance.

“This is convergent with the results of various anthropological studies on hunter-gatherers that suggest early human societies were more egalitarian than those of today,” Huchard said.

Newton-Fisher also cautioned it is premature to suggest that much can be gleaned from the study about humans, noting the branch of primates to which humans belong – apes and catarrhine monkeys – is one that exhibited strict male dominance in the study.

The “alpha male” is by no means a universally disproven myth among primates, Huchard said – but it can no longer be considered as the norm. “It’s how it is in baboon societies and how it tends to be in chimpanzee societies. But it’s a minority.”

Source link