The development of human female competition: Allies and adversaries

Abstract

Throughout their lives, women provide for their own and their children's and grandchildren's needs and thus must minimize their risk of incurring physical harm. Alliances with individuals who will assist them in attaining these goals increase their probability of survival and reproductive success. High status in the community enhances access to physical resources and valuable allies. Kin, a mate, and affines share a mother's genetic interests, whereas unrelated women constitute primary competitors. From early childhood onwards, girls compete using strategies that minimize the risk of retaliation and reduce the strength of other girls. Girls' competitive strategies include avoiding direct interference with another girl's goals, disguising competition, competing overtly only from a position of high status in the community, enforcing equality within the female community and socially excluding other girls.

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Cite this article: Benenson JF. 2013 The
development of human female competition:
allies and adversaries. Phil Trans R Soc B 368:
20130079.
http://dx.doi.org/10.1098/rstb.2013.0079
One contribution of 14 to a Theme Issue
‘Female competition and aggression’.
Subject Areas:
behaviour
Keywords:
female competition, development,
girls, women, strategies
Author for correspondence:
Joyce F. Benenson
e-mail: joyce.benenson@gmail.com
The development of human female
competition: allies and adversaries
Joyce F. Benenson
Emmanuel College, 400 The Fenway, Boston, MA 02115, USA
Throughout their lives, women provide for their own and their children’s
and grandchildren’s needs and thus must minimize their risk of incurring
physical harm. Alliances with individuals who will assist them in attaining
these goals increase their probability of survival and reproductive success.
High status in the community enhances access to physical resources and
valuable allies. Kin, a mate, and affines share a mother’s genetic interests,
whereas unrelated women constitute primary competitors. From early child-
hood onwards, girls compete using strategies that minimize the risk of
retaliation and reduce the strength of other girls. Girls’ competitive strategies
include avoiding direct interference with another girl’s goals, disguising
competition, competing overtly only from a position of high status in the
community, enforcing equality within the female community and socially
excluding other girls.
1. Introduction
Why should women differ from men in competitiveness? Past research focused on
the greater variance in men’s reproductive success and concomitantly women’s
lack of need to compete [1,2]. More recent research on non-human females
demonstrates that females do indeed vary significantly in reproductive success,
in some species as much or more than males do [3–5]. For humans, health, phys-
ical resources, alliances and community status influence reproductive success, but
women confront unique constraints.
2. Mothers’ worries
Like most female mammals, human mothers must remain healthy and safe
enough to protect their finite supply of oocytes, then later gestate and lactate.
They also must provide physical resources, including food, shelter and territories,
for themselves and their dependent offspring throughout their lifetimes [6– 10].
(a) Allies
Human mothers benefit more than most primates from allies who provide phys-
ical resources and child care [11– 13]. Compared with other great apes, human
females reproduce more rapidly [14,15] and produce unusually altricial offspring
[7], so assistance enhances reproductive success. Like most mammals, mothers
bear primary responsibility for unweaned infants [16,17], but in humans, allo-
mothers can care for older, but still dependent children [12,18]. Because women
often reside patrilocally, bilocally or neolocally [19], they typically disperse
from their natal families for part of their adult lives [20]. Therefore, kin are not
always available [21,22]. A mate and affines who share genes with a woman’s
children consequently provide valuable assistance. Besides a mother’s older
children and her own mother, a mother-in-law [12,13,23] and a long-term mate
[24– 27] can provide physical resources, child care for weaned children and
maintenance of a woman’s status in the community [16,17,28].
For both sexes, unrelated same-sex peers constitute primary competitors.
Women are less likely than men to engage in cooperative group activities
with unrelated same-sex peers beginning in childhood [29– 31] and continuing
through adolescence [32,33] into adulthood [34–39]. In hunter – gatherer,
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agricultural and modern communities, young and middle-age
men benefit from the support and skills of similarly aged men
during hunting and warfare and other group pursuits. Men’s
hunting success and intergroup victories increase the reproduc-
tive success of the whole community [35,40]. By contrast, no
studyhas demonstrated the reproductive benefits of cooperation
with unrelated women as opposed to female kin.
Nonetheless, one or two carefully chosen unrelated female
friends can provide emotional support [41]; protection from
and assistance with competition against rivals [42] and low
cost aid with child care [38], although female kin can perform
similar functions. Trusted female friends however offer respite
from the high costs associated with kin, spousal and affinal
relationships and share a greater investment in competing
against same-age competitors by enforcing rules regulating com-
petition. Ultimately however, a woman invests first and foremost
in her own spouse, children and allomothers [12,13,38,43].
(b) Status
Across cultures, high status in the community increases both
women’s and men’s survival and reproductive success,
enhancing access to physical resources and valuable allies
for themselves and their children [44 – 47]. A high biological
market value in a community based on personal (e.g.
energy level, attractiveness, height, sociability, toughness
and generosity) and familial characteristics (e.g. resources,
number of kin, community connections and skills) determine
status by allowing an individual to reap benefits from and
dispense punishments to other community members [48].
Women typically occupy lower status positions in the com-
munity than men however, even in the most egalitarian
hunter–gatherer societies [49–51]. Forming a pair bond
with a higher status mate therefore increases a woman’s
status [24], especially if she lacks high-status kin [50]. High
status in the community allows a woman to increase her
own children’s success by reducing the reproductive poten-
tial of lower status women through harassment or harming
their children [52–54].
Within the female community, status is calculated differ-
ently. Generation and age determine status among female kin
[32]. By contrast, unrelated women enforce equality [41,55].
Unlike unrelated men, status is not earned through skills and
allegiance to a large interconnected group [56,57]. Instead, a
woman forms several separate, exclusive, one-on-one friend-
ships within the larger female community [41,58,59]. Female
friends prohibit competition by one another and other acquain-
tances by punishing superiority [58,60], requiring reciprocity
[59] and exhibiting a low threshold for dissolving relationships
when conflicts arise [61–63]. These prohibitions do not apply
to relationships with kin, a spouse or affines [59].
3. Principles of female competition
Women compete to acquire resources for their kin, spouse and
affines and a few trusted female friends; to protect their own
and threaten other women’s alliances, especially marriages,
given men’s greater interest in polygamy; and to prevent
other women from reducing their family’s market value and
opportunity for status enhancement in the larger community
[64]. Three principles appear to underlie female– female
competition. First, to protect their bodies for lifelong child
care, women employ competitive strategies that reduce the
probability of incurring physical harm through retaliation
[9,10]. Avoidance of direct interference competition, disguising
competition and competing only when there is little prob-
ability of retaliation, such as having high status in the
community, all minimize chance of injury.
Second, because unrelated females rarely cooperate as a
group, one woman’s success brings little benefit to the
female community. Demands for equality within the female
community function to impede individual women’s attempts
to gain additional physical resources, valuable allies or status
for themselves. High-achieving women have little incentive
to invest in other women, so most women benefit from pun-
ishing striving peers. By contrast, trusted, equal friends can
benefit from reciprocal investment.
Third, lack of group cooperation also underlies a more
extreme strategy: social exclusion [65,66]. Ultimately, with
the exception of a few selected friends, additional women
in the community are prime competitors for physical
resources, mates and status in the community [65]. Elimin-
ation of a non-friend by a coalition therefore reduces the
number of competitors. Proximately, a coalition minimizes
the probability of harmful retaliation by outnumbering the
victim [67]. Female friends likely serve most readily as
coalition partners in acts of social exclusion: a man would
be less willing to evict a potential sexual partner, whereas
female kin who differ in age from the victim would find
her less threatening.
Five competitive strategies result from these principles:
(i) avoid interference competition, (ii) disguise competition,
(iii) compete overtly only if high-ranked in the community,
(iv) enforce equality among female peers and (v) use social
exclusion. Girls employ these strategies against female
same-sex peers beginning early in childhood.
4. Development: who helps and who hinders?
(a) Infancy (0– 2 years): staying alive and connected to
a caregiver
Female infants are born more physically mature and less vul-
nerable than males to physical and social insults [68– 70], yet
most mothers prefer sons over daughters [71,72]. A mother
typically makes the final decision as to whether to keep a
newborn alive and how much to invest in it [73]. Although
either sex can be preferred [11,73], males’ higher status
translates into females’ greater vulnerability to infanticide.
Currently, more than 100 million girls have been murdered
in Asian and African countries [51,74]. Selective mistreatment
of female infants, from outright killing to deprivation of food
and medical care, continues to be widespread [51,75].
Paradoxically therefore, it is likely that a mother is both a
girl’s primary adversary and ally in infancy. While a father,
other kin and affines indirectly influence a mother’s decision
to invest in her daughter [11,73], it is an infant girl’s mother
who typically keeps her alive and healthy. Attracting her
mother’s investment therefore is absolutely critical [11]. A
girl’s direct competitors are current or future brothers, and
older sisters. Establishing a bond rapidly with a mother
and other caregivers is critical.
A female newborn may compete for her mother’s invest-
ment by being easier to care for and more interactive than her
brothers [76–78]. Parents tolerate crying less in female than
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male infants: female infants are viewed as weak if they cry,
whereas the reverse is true for males [79]. From birth,
female neonates exhibit fewer negative emotions, less intense
activity [80–82] and greater self-regulation [83]. Further, com-
pared with males, female infants look more at a caregiver’s
face [84] and more accurately identify adult emotions [85].
They also smile more and make more eye contact [86,87].
When they become mobile, they remain in closer proximity
to their mothers [88,89]. By 14 months, female infants
comply more than males with parental requests [90– 92].
(b) Early childhood (2– 5 years): learning to assist with
and obtain assistance from kin
The relationship between a girl and her mother and other
female relatives may be the emotionally closest and most
enduring that exists [19,23,93– 96], especially if a girl lives uxor-
ilocally after marriage. Across diverse cultures, compared with
boys, in early childhood, girls offer more assistance to mothers
with child care and domestic responsibilities [21,95]. Beginning
at age 2, girls mind younger siblings, and at all ages girls are
more interested than boys in babies [97].
Reciprocally, in natural settings across cultures girls are
more likely than boys to seek assistance from mothers and
other adults [98]. Experimentally, 3- to 5-year-old girls requested
more assistance from an adult than boys on structured tasks
[99 –101]. Cross-culturally, mothers talk more and use more sup-
portive speech with daughters than sons [102], and daughters
remain physically closer to mothers than sons do [95,103]. For
girls, proximity to adults facilitates resource acquisition [104].
In preschool settings, the more same-sex peers present, the
closer 3- to 5-year-old girls remain to adults, whereas the con-
verse is true for boys [105]. A supportive mother or substitute
female adult therefore likely exerts the greatest influence on a
young girl’s ability to satisfy goals without incurring high costs.
When female adults are occupied, a girl spends time how-
ever with unrelated female peers owing to their common
interests and because unrelated boys can be dangerous
[106]. Further, from birth onwards, unrelated boys exhibit dif-
fering interests than females [84], so that mobile girls and
boys segregate themselves spatially [107]. Unrelated girls
who share goals and strategies, but no genetic interests,
constitute both a girl’s companions and primary competitors.
In naturalistic settings, after 2 years of age, girls often
avoid boys, most probably owing to boys’ rougher play styles
[107– 109]. At 33 months, when unfamiliar female and male
peers were paired, girls were more likely to withdraw, behave
passively, cry and seek proximity to their mothers when
playing with a boy than a girl [110]. Between 2 and 3 years,
cross-culturally boys begin to denigrate girls [95,111–113].
By age 4, despite similarities in size and strength, girls cede
physical resources to boys. In a study of resource utilization, a
child could view movies if another child pressed the light, and
a third child turned a crank [114]. When groups of two girls
and two boys were formed, girls viewed the movies less than
one-third as much as boys did. Even the toughest girls
viewed the movies less than boys. Boys’ physical attacks,
displacement, threats and commands deterred girls.
When mixed-sex pairs of 3- to 5-year-old children operated
the movie viewer, and no assistance with the light or crank was
required, girls likewise gained less viewing time [104]. When a
passive adult was present however, girls insisted on longer
turns. Young girls rely on adults to protect their interests
more than boys do, remaining closer to preschool teachers
[115] and mothers [103]. Ultimately, however, girls compete
against other girls, not boys.
(i) Avoid interference competition
Frequency of physical aggression peaks between 2 and 4 years
for both sexes, but girls are less aggressive [116–118]. Whereas
girls use physical force to resolve conflicts over possessions and
space earlier than boys, after 24 months girls use less bodily
force (pushing, pulling, kicking or hitting the peer’s body)
than boys in conflicts over resources or territory [119– 121].
Girls also are less likely than boys to directly verbally interfere
(command, threat, prohibit or heckle; [60,122,123]). Instead,
they use more subtle competitive strategies.
(ii) Disguise competition
Better disguised forms of competition minimize retaliation.
Girls use complex verbal and non-verbal tactics and physical
movements that appear non-competitive on the surface. By
age 3, girls far more than boys emphasize their caring and
egalitarian natures [124,125], and ‘niceness’, which means
concealing their goals [126]. ‘What girls learn to do with
speech is cope with the contradiction created by an ideology
of equality and cooperation and a social reality that includes
difference and conflict’ [60, p. 205].
Young girls’ ‘double voice discourse’ disguises conflicts
over resources by expressing anger quietly, using false voices
attributable to others to make demands, suggesting postpone-
ment of equal outcomes and shifting attention to cooperation
from conflict [127]. Smiles, politeness (‘I’m sorry’ ‘thank
you’), qualifiers (‘maybe’ ‘probably’ ‘yes, but’), questions
rather than direct commands (‘Will you do this?’), statements
that include tags (‘It is mine, right?’), inclusion of antagonists
(‘Let’s do this’) and other ways of mitigating or softening con-
flict constitute girls’ primary means of obtaining goals
[123,127]. Further, girls are more likely than boys to express
agreement, allow a speaker to finish, acknowledge the prior
speaker’s words and provide justifications that connect rather
than oppose others’ views [122,128]. Girls ‘possess verbal
negotiation skills that enable them to confront without being
very confrontational; to clarify without backing down; and to
use mitigators, indirectness, and even subterfuge to soften
the blow while promoting their own wishes’ ([127], p. 61).
To illustrate, a triad of 3-year-old girls was attempting to
gain a valuable resource, a pickle, in their preschool kitchen:
Sue: And strawberries for dinner, right?
Mary: And the- this for dinner. (Mary puts the pickle in a pot on
the stove)
Sue: And the pickle. Do you like pickle? (Sue takes the pickle
out of the pot)
Mary: And this (the hamburger) is for dinner. (Mary pulls the
hamburger and pickle out of Sue’s hand and puts them back in
the pot)
Sue: No, they aren’t for dinner, no, Lisa wants pickles. (Sue
tries to grab the hamburger and pickle back from Mary but she
holds on and puts them back in the pot) ([129], pp. 16–17)
By contrast, boys compete overtly:
Kevin: (at the table) Pickle. (takes the pickle)
Nick: I’m cutting- I’m cutting- No, I have to cut that! (Nick
tries to take pickle back from Kevin)
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Kevin: No, I cut it.
Nick: No! No, no, no! You’re the children!
Kevin: No, I’m not! [129, p. 22]
(iii) Compete overtly only if high ranked in the community
Girls with high status in the community can compete more
directly, because the threat of retaliationis lowered. In preschool
dyadic resource conflicts, compared with boys, girls use less
physical aggression and submit more. A few girls with high
status in the class however refused to back down [130,131].
Likewise, when the movie viewer study was repeated with
4- to 5-year-old children in same-sex groups of four [132], girls’
and boys’ groups gained equal viewing time. Girls’ groups
were less egalitarian however than boys’ groups: one girl
dominated and another girl was not allowed to participate.
Dominant girls who viewed the most movies used more com-
mands, physical force, blocking, pushing and disruptions than
girls who never viewed the movies. By contrast, boys who
viewed the movies the most and least did not differ in verbal
or physical tactics. Overall, however, girls used less bodily
force or physical contact than boys did.
Similarly, high status more than low status 4- to 5-year-old
Turkish girls obtained the best roles during pretend play, then
issued more commands and directives to other girls [133].
American 3-year-old girls follow the same strategy: one gains
a superior ‘pretend’ role, then commands others [134]. Only a
high-status girl dispenses with egalitarian behaviour, which
she resumes when a similarly high-ranked girl enters [125].
(iv) Enforce equality among girls
Eliminating all uneven resource distributions and status differen-
tials provides an effective counterstrategy. Linguistic researchers
conclude that ‘a girl cannot assert social power or superiority as
an individual’ ([60], p. 205) without risking other girls’ denigra-
tion [133]. By age 3, girls enforce equality. Compared with boys,
across diverse cultures girls avoid employing signifiers of high
status with same-sex peers, including commands, boasts, pro-
vision of information or joke-telling [60,122,133]. Another
movie viewer study with same-sex groups of four 3- to 5-year-
olds demonstrates girls’ dislike of superior girls: those girls
who took control and viewed the movies longest were less
liked by all their female classmates than those girls who rarely
viewed the movies [135]. The opposite was true for the boys.
(v) Use social exclusion
Exclusion constitutes a more extreme strategy. By age 3, com-
pared with boys, girls more often disparage a same-sex peer
in conversations [136,137]. Experimentally, when same-sex
triads of 4-year-olds received only one valuable resource,
girls were more likely than boys to use social exclusion in
which two friends ganged up on the third. By contrast, boys
individually directly attempted to grab the resource [138].
(c) Middle childhood/juvenile period (5– 12 years):
developing an intimate, exclusive, reciprocal bond
with another girl
Cross-culturally, responsibility for the care of younger siblings
increases in middle childhood [95,139]. Further, when enough
unrelated children are present, universally girls interact almost
exclusively with other girls, and not boys [95,107,140].
Segregation by sex occurs partially because boys avoid
[113,141] and bully [142] girls. When unsupervised by adults,
girls allow boys to dominate them across domains and cultures
[143]. Othergirls also providea respite fromfamilial responsibil-
ities, share similar interests and provide emotional support [41].
Girls form an intimate, exclusive friendship with another
girl, isolated from other girls [55,144]. Two girls bond
through reciprocal verbal discussions of similar personal vul-
nerabilities, particularly concerns about alliances with other
girls and family members [41]. Unconditional acceptance,
exclusivity and loyalty further define the middle childhood
female friendship [63,145]. Imagining its potential dissolution
generates feelings of devastating loss [146], foreshadowing a
commitment to a long-term heterosexual bond.
Despite their appeal, isolated female pair bonds are not
destined to last and frequently endure for shorter periods
than male friendships that are embedded within a larger
group [144,146– 148]. Further, the intimate, repetitive discus-
sions of personal difficulties between girls can promote
negative emotions, including depression [149]. Consequently,
across cultures in middle childhood girls continue to rely on
and maintain proximity to mothers, female relatives, teachers
and other female adults [37,95,150,151].
Competitive strategies of early childhood become accentu-
ated between girls in middle childhood as they vie for a female
friend [152]. Initiation and preservation of female friendships
require continually expelling interlopers and enforcing loyalty,
exclusivity, reciprocity and equality. Girls tolerate conflicts less
than boys with same-sex friends, as they proceed from one
female partner to the next searching for another girl who
meets the requisite standards [61,63,153]. Even though
female bonds are the focus in middle childhood, the highest
status girls in the community begin to evaluate specific boys
as potential mates [141].
(i) Avoid interference competition
Across cultures, girls continue to use less direct physical and
verbal (yelling, cursing or extreme hostile language) aggression
than boys [116,118]. In school competitions, a girl competes
primarily against herself, as in jump rope, hopscotch, exercise
or academics, whereas boys engage in zero-sum activities
that require actively interfering with another’s goals [30,154].
Experimentally, when 10-year-old children played interfer-
ence and non-interference versions of the same game in groups
of four same-sex peers, compared with boys, girls avoided
interfering with another’s goals [155]. Girls physically removed
another child’s tokens, only when it was necessary to win a
prize, and then they averted their gaze. When winning did
not require taking another’s tokens, girls avoided it. By con-
trast, boys took their same-sex peers’ tokens, regardless of
whether it improved their own probability of winning. Like-
wise, when groups of four 6- or 9-year-old same-sex children
were asked to choose a leader, no sex differences occurred in
length of negotiations. Girls however exhibited more discom-
fort than boys during negotiations, and for girls, the longer
the negotiations, the greater the discomfort [156].
(ii) Disguise competition
When possible, disguising competition is safer than competing
overtly [60]. In same-sex conversations, compared with boys,
girls use half as many assertive or dominating speech acts
designed to control a same-sex peer’s behaviour [157]. Further,
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girls use more affiliative speech acts than boys, including pro-
vision of information or invitations to play. Likewise, when
same-sex pairs of 10- to 14-year-old close friends played a
game with a same-sex confederate who was trained to criticize,
boast, boss and otherwise behave unpleasantly, girls made
fewer aggressive and assertive statements than boys to the con-
federate [158]. Instead, girls made more subtle aggressive non-
verbal facial and bodily non-contact gestures than boys.
Similarly, when 11- to 12-year-old Finnish children
described the behaviours of same-sex classmates whose goals
were thwarted, girls reported more instances than boys of dis-
guised competition, including telling an untruth behind the
target’s back, becoming another’s friend to take revenge on
the target, telling others not to be friends with the target, sulk-
ing, putting the target to the side, pretending not to know the
target and remaining angry [159]. By contrast, girls reported
fewer instances of direct interference with a target’s goals,
including tripping the target, taking the target’s objects, swear-
ing at the target, kicking, hitting or shoving the target, and
repeated expressions of anger. Likewise, in 17 classrooms of
11- to 15-year-old British schoolchildren, compared with
boys, girls reported more gossiping and dirty looks and less
making fun of others and hitting [160].
(iii) Compete overtly only if high ranked in the community
When overt bullying occurs, high-status girls bully lower status
girls, just as high-status boys bully lower status boys [142],
though girls are less likely to bully than boys [161]. More com-
monly, high-status girls use less overt strategies. Across diverse
cultures when girls assist mothers in domestic chores, ‘pro-
social dominance’ is used by older girls to control younger sib-
lings’ behaviours [95]. By extending this strategy to pretend to
hold a position of authority with unrelated same-age girls, a
girl can dominate others and pursue her own interests. For
example, ethnographic research in an African– American
working-class neighbourhood demonstrated that girls
attempted to control one another by assuming the mantle of
an authority figure, such as a mother or teacher [162].
(iv) Enforce equality among girls
In response, girls denigrate superior-acting girls. Girls evaluate
one another in terms of ‘niceness,’ that is lack of competitive-
ness, whereas boys like high-status, competitive boys
[56,163]. For example, 10- to 11-year-old American girls
engaged in activities where everyone played the same role,
such as turn-taking games or jump rope, with no winners
acknowledged, whereas boys played zero-sum team games,
with role and status differentiations, after which winners cele-
brated [30]. Likewise, working-class 8- to- 15-year-old
African– American girls disparaged superior-acting girls,
whereas boys continually vied to be superior [162]. Experimen-
tal investigation of 6- and 10-year-old children’s responses to
attaining higher in same-sex dyads showed that victorious
girls exhibited more discomfort than boys after winning a
game [156]. Most directly, when a same-sex confederate dis-
played high-status behaviours, such as boasting and bossing,
compared with boys, girls rated the confederate as meaner
and themselves as angrier at the confederate [158].
(v) Use social exclusion
Any lone girl risks ostracism, but superior-acting girls are
particularly attractive victims. Social exclusion in middle
childhood typically consists of female friends forming an alli-
ance to eject a lone target from the community [162]. A
longitudinal, naturalistic study of same-sex triads of 9- to 12-
year-old American schoolchildren demonstrated that more
female than male triads excluded one member to form a pair
bond [164]. Experimentally, when a same-sex newcomer was
introduced to pairs of 6-year-olds, initially girls were more
likely than boys to ignore, avoid and refuse to interact with
the newcomer [165]. Likewise, 8- to 12-year-old children nomi-
nated more girls than boys as using social exclusion and threats
to end a friendship [166]. Finally, in a studyof 10-year-old Brit-
ish children who competed to create a drama to win a
monetary award, more female than male groups ganged up
on a lone individual in their same-sex groups [167].
(d) Adolescence: finding a mate, bearing a child
Humans of both sexes experience an extended period of ado-
lescence [14,168]. Girls’ adolescence however is briefer
[15,169], requiring earlier acquisition of adult skills. In 40
developing countries, 50% of girls marry before age 18, and
for 75% first births follow within 2 years [170]. By contrast,
men often marry after age 30. Age at first marriage strongly
influences life histories of both a girl and her children [170],
in part because women are up to three times less likely
than men to re-marry [6,49,171]. Consequently, a woman’s
first marital partner is much more important than a man’s.
Further, unlike boys, girls appear sexually mature well
before they become fecund [15,169], increasing pressure on
girls to marry early [172].
In adolescence, girls’ primary allegiance switches from
natal kin to a husband and first child, with an intimate
female friend bridging the transition. Where a girl resides
matrilocally, the transition is eased [50]. Cross-culturally,
when possible girls and young women remain closer to their
mothers, other female kin and natal kin [32,95,96] and rarely
aggress against older kin or affines [54]. Across 173 cultures,
adolescent girls spent more time than boys in close proximity
to intergenerational familial members, assisting with domestic
chores [32]. In adolescence and adulthood, compared with
males, girls and women still view parents and parental substi-
tutes as more important than an unrelated close friend for
providing both instrumental and emotional assistance [37].
Adolescent girls more than boys ask medical and psychologi-
cal personnel, teachers and other authority figures for
assistance [173]. Even in polygynous marriages, a newlywed
female occasionally brokers an agreement with an older co-
wife, in which the new wife provides medical care to the
older wife in exchange for the older wife’s assistance [53]. A
few trusted female friends who meet the requisite standards
can provide emotional support [41] and serve as allies target-
ing rivals, or reciprocally as a bulwark from rivals’ attacks.
Nonetheless, in most societies, a husband becomes a girl’s
primary ally, providing physical resources, alliances and
community-wide status for a woman and her children.
Even though husbands dominate and even abuse women
[51], a woman’s reproductive success may be most influenced
by her husband’s connections and status. As researchers who
study the Tsimane conclude, ‘A good mate can mean the
difference between a lifetime of support vs. a lifetime of fend-
ing for one’s self and one’s children’ ([174], p. 203).
Accordingly, Ache women devoted 55% of their total time
foraging exclusively to helping their spouse [38].
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As earlier, adolescent girls avoid competing against boys.
Experimentally, when early adolescent Hopi Indians and
African–Americans competed, girls lost to boys [175]. Like-
wise, older adolescent European – American girls let boys
dominate during dyadic [176] and group activities [177].
Instead, girls compete against other girls for a valuable
mate. Although two girls can support one another emotion-
ally, as well as form protection from and coalitions against
a rival, co-rumination about relationships increases
depression and anxiety markedly in adolescence [178].
Further, girls betray one another to form bonds with boys.
Girls report greater anger, hurt and jealousy than boys
towards close same-sex friends [179], especially if they were
abandoned for a romantic partner [174,180]. Across 137
societies, 91% of women’s competitive acts were targeted
towards women, most frequently over men’s attention,
emotional investment, goods, services and sexuality
[53,54,174], but also over broken social obligations, meat
theft and friendships in which one young woman allied
with another one against her former friend.
(i) Avoid interference competition
Adolescent girls across diverse cultures still rarely directly
interfere with another female’s pursuit of her goals [32,116],
even eschewing zero-sum sports games during exercise or
individual athletic activities [181]. Although serious physical
interference competition peaks for both sexes between 15 and
25 years, females use it 1/10 as often as males [106,116,182].
Young women’s use of violence across cultures typically
occurs when her own or her children’s survival is jeopardized
[54], in the absence of kin [50], when mates and resources are
in short supply [183– 185], when co-wives share a husband
[53] and where marriages are not arranged [52].
(ii) Disguise competition
More commonly, competition is disguised so thoroughly that
the competitors themselves are not even conscious they are
competing [126]. Girls compete frequently through attempts
to control other girls’ romantic relationships [186]. Across
cultures, girls’ manipulation of another girl’s alliances with
same-sex and other-sex peers increases in frequency and
intensity in adolescence compared with earlier and relative
to boys [116,187– 189]. Girls specifically attempt to end
romantic partnerships by maligning another girl [163],
often through denigration of the other girl’s sexual reputation
to a potential spouse [190,191]. Through denigration of
female peers, a girl reduces the number of serious competi-
tors for a mate. Records of conversations of pairs of older
adolescent girls and boys showed that a higher proportion
of girls’ conversations contained negative statements about
a same-sex peer [192]. Further, female conversational part-
ners were more likely than male partners to respond
positively to an initial denigration. Reputation denigration
of a female competitor provides a powerful tool to increase
a girl’s own chances of finding a valuable mate.
(iii) Compete overtly only if high ranked in the community
Across diverse cultures, attributes considered markers of
females’ reproductive success, including appearance and
energy level, as well as access to physical resources (high-
socioeconomic status), determine a girl’s attractiveness to
potential mates and define high status in the community
[24,163,193]. Studies of Canadian and American adolescents
showed that both high-status girls and boys used overt and
disguised forms of aggression more often [142,188,194] and
in the Netherlands were more likely to be bullies, although
girls bullied less than boys [195]. Similarly, high-status British
adolescent girls occasionally physically harmed and often
overtly manipulated the social relations of lower status girls
in order to control access to high-status boys [145].
(iv) Enforce equality among girls
High-status adolescent girls elicit more respect from other girls
than in earlier years, because the community of girls is more
spatially connected to the male community than before. Lower
status females who form alliances with high-status females
theoretically can increase their access to valuable mates. Adoles-
cent girls consequently compete more than boys to form bonds
with high-status same-sex peers [163,196]. A lower status girl
will surrender all her other friendships and accomplishments
in an attempt to form a bond with a high-status girl. Practically,
this rarely produces pay-offs, as a high-status girl profits little
from allying with anyone but another high-status girl [163,196].
This produces even stronger denigration of high-status
adolescent girls than earlier [196]. Within the girls’ peer
group, high-status girls who interfere with another girl’s
goals invite derision and social exclusion [162,163,193,196].
Niceness and equality remain the female community’s
norms. Girls’ primary justification for being mean is that
another girl is acting superior. Even in the rare girl gangs
that exist, the leader must behave as an equal [184].
In the Netherlands, in an implicit association computerized
task, girls approached the names of same-sex high-status early
adolescents more slowly than low status adolescents, whereas
the reverse was true for boys [195,197]. Likewise, high status
and liking were unrelated or negatively related for early and
middle adolescent American girls, but positively related for
boys [198,199]. Further, high status at ages 15–16 years pre-
dicted lack of liking 2 years later for girls, but liking for boys.
Likewise, Canadian girls reported feeling greater jealousy
than boys if a same-sex friend were more successful [179]. Reci-
procally, American [126] and Canadian [200] girls were more
likely than boys to believe that if they were more successful
than a close same-sex friend at making a new same-sex
friend, excelling in academics or athletics or forming a romantic
relationship, they would be less liked by their same-sex friend.
The sex difference was strongest for finding a romanticpartner.
(v) Use social exclusion
Girls with high status in the community can more easily socially
excludelower status girls, because they attract more female and
male allies. Ethnographic studies in American, English and
Australian schools demonstrate the common use of both overt
and disguised social exclusion by high-status adolescent girls
as they attempt to ostracize one another, lower status girls
and newcomers [145,201–203]. If lower status girls can form a
temporary large group however, they can exclude a lone
high-status girl [162]. This is even more true if they can elicit
the support of the larger community, meaning boys [201,202].
Experimentally, when pairs of same-sex American young
adolescent friends were introduced systematically to a same-
sex newcomer, compared with boys, girls rated the newcomer
less positively, took longer to speak to the newcomer and incor-
porated fewer of the newcomer’s ideas [204]. Likewise, older
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adolescent French Canadian girls were more likely than boys to
use social exclusion ina computerized game [42], and Canadian
girls reported being socially excluded more frequently than
boys [65].
5. Conclusion
In summary, from early childhood through old age, human
females’ reproductive success depends on provisioning, pro-
tecting and nurturing first younger siblings, then their own
children and grandchildren. 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. When a
girl has high market value in the community, she is afforded
greater protection and can compete more openly without fear
of retaliation. Within the female community, girls reduce
competition by demanding equality and punishing those
who openly attempt to attain more than others. Social exclu-
sion 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.
Girls reach adulthood earlier than boys, frequently marry-
ing and bearing their first child before age 20. Because they will
re-marry less often than boys, produce children faster and bear
primary responsibility for young children, girls have less
opportunity than boys to change the course of their reproduc-
tive careers. By late adolescence, a girl’s success in finding a
valuable spouse can influence her entire reproductive career.
Forming alliances with kin, a few trusted female friends, then
a spouse and affines, while reducing the power and number
of female competitors, enhance the probability that a
woman’s children and grandchildren will prosper.
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