Across a wide array of cultures, boys are known to use more direct aggression than girls, who seemingly prefer less obvious yet more complex ways of expressing hostility toward others. Now, two studies published in Philosophical Transactions of Royal Society B. explain how and why women have evolved to use social exclusion, criticizing appearances, spreading rumors — indirect aggression — as their favored form of competitive strategy. But what are girls competing for?

“A clear way that indirect aggression serves an individual's goal is by reducing her same-sex rivals' ability, or desire, to compete for mates,” Tracy Vaillancourt, professor at the University of Ottawa School of Psychology, wrote in her paper. “Do human females use indirect aggression as an intrasexual competition strategy?”

Having secured a mate, though, does not end the competitive games for an individual woman; in fact, they have only just begun. For the rest of her life, a woman accepts responsibility for providing resources, including food and shelter, for her offspring.

“To safeguard their health over a lifetime, girls use competitive strategies that reduce the probability of physical retaliation, including avoiding direct interference with another girl's goals and disguising their striving for physical resources, alliances and status,” Joyce F, Benenson, professor of psychology, Emmanuel College, wrote in her paper. “The development of human female competition: allies and adversaries.”

Competitive Strategies

In her review of current literature on the subject, Vaillancourt reiterates previous suggestions that females make a greater parental investment than males and so “the costs associated with direct aggression (i.e. physical injury and even death) are too great.” Self-protection, then, is a key reason for using indirect aggression, which, Vaillancourt asserts, is highly effective. In fact, it works very well and so is used primarily by girls and women when they are at the peak of their reproductive value. Moreover, Vaillancourt notes, the frequent aim of indirect aggression is to suppress the sexuality of other females, which can be neatly accomplished by ostracism and derogatory gossip.

In a previous experiment, Vaillancourt and her co-researcher randomly assigned young women who had first been paired off to one of two conditions. The first group of participants had their conversation interrupted by an attractive female dressed in sexy clothing; the second group by the same woman dressed in a conservative manner. Secretly, the researchers video-recorded participants’ reactions; with the exception of two women, all of the participants who dealt with a “sexy” interruption engaged in indirect aggression.

Vaillancourt notes that indirect aggression need not be conscious to be in play and is “typically accomplished in a concealed way which diminishes the risk of a counterattack.” Despite the smaller risk of direct or even physical confrontation, it is a competitive strategy that is not without peril. After all, derogation of a rival may call a man’s attention to her or simply reveal a woman’s unkindness. In the end, though, “the benefits of using indirect aggression seem clear—fewer competitors and greater access to preferred mates, which in ancestral times would have been linked to differential reproduction rates, the driving force of evolution by sexual selection,” Vaillancourt wrote.

Elaborate Forms of Conflict Avoidance

To derive her theories of female strategy and behavior, Benenson employs methods drawn from the fields of animal behavior, evolutionary biology, cognition, economics, anthropology, neuroscience, sociology, and developmental psychology. In essence, the crux of her argument is that human mothers are like most female mammals — they are engaged in a struggle to remain healthy and safe enough to protect a finite supply of oocytes. Upon clearing the twin hurdles of gestation and lactation, they must then compete to provide physical resources for themselves and dependent offspring throughout their lifetimes.

Although men are in competition with other men, they benefit from the support and skills of other men during group pursuits (such as hunting or warfare) and so each man’s individual success is enhanced by the success of his community. This is not the case among unrelated women, who invest first and foremost in their spouses, children, and allomothers — those who help them raise their children, generally sisters or kin. Benenson identifies the five competitive strategies used by girls and women against female same-sex peers beginning all the way back to their earliest childhoods:

  1. Avoid interference competition.
  2. Disguise competition.
  3. Compete overtly only if high-ranked in the community.
  4. Enforce equality among female peers.
  5. Use social exclusion.

Benenson notes the complex verbal and non-verbal tactics a girl learns at a very young age to disguise her attempts to obtain her goals and thus mitigate or soften conflict. These methods would include smiles, politeness (‘I'm sorry,’ ‘thank you’), qualifiers (‘maybe,’ ‘probably,’ ‘yes, but’), as well as questions rather than direct commands (‘Will you do this?’).

“Within the female community, girls reduce competition by demanding equality and punishing those who openly attempt to attain more than others,” Benenson wrote. “Social exclusion by several girls of lone female victims provides a safe strategy for increasing physical resources, allies and status opportunities by decreasing the number of competitors.”

Sources: Vaillancourt T. Do human females use indirect aggression as an intrasexual competition strategy? Philosophical Transactions of Royal Society B. 2013.

Benenson JF. The development of human female competition: allies and adversaries. Philosophical Transactions of Royal Society B. 2013.