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The Development of Childhood Aggression:

Boys Will Be Boys, But What About Girls?

Nicki R. Crick, Ph.D.

Director, Institute of Child Development

Distinguished McKnight University Professor

Birkmaier Professor of Educational Leadership

University of Minnesota

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Traditional Views of Aggression For decades, research and theory

focused on discovering why, how, and when “boys will be boys”.

In their classic book on gender differences Maccoby & Jacklin (1974) cited aggression as one of the only “true” gender differences in development. Boys’ aggression > Girls’ aggression

starting at an early age and continuing across the lifespan

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What Do More Recent Theories Tell Us About Gender and

Aggression?

Beginning at preschool (4 - 5 years), girls are socialized away from externalizing problems (e.g., aggression) and toward internalizing problems (Keenan & Shaw, 1997).

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Also….

Aggressive behavior among girls does not typically appear (or reappear) until adolescence and, even then, boys are more aggressive than girls (Keenan & Shaw, 1997; Moffitt et al., 2001; Silverthorn & Frick, 1999).

Apparent Conclusion: Aggression is not a very salient problem for girls (Crick & Zahn-Waxler, 2003).

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So….”What About Girls”?

Sugar and spice and everything nice….

OR Not? Have we missed something?

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Limitations of Past Theory and Research on Aggression

The majority of past studies and theories have been dominated by definitions of aggression that are male biased.

Most previous investigations have focused almost exclusively on boys and, as a result, have often excluded girls as participants.

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Relative to girls, boys tend to be more concerned during social interaction with physical dominance, instrumental concerns, territoriality, etc.

The aggressive behaviors most characteristic of boys tend to reflect these themes or orientations.

These are the types of behaviors that have been traditionally assessed in past studies of aggression.

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Physical Aggression

Includes behaviors in which physical damage (or the threat of physical damage) serves as the agent of harm.

Includes behaviors such as threatening to beat up a peer unless they comply with a request; using physical intimidation as a retaliatory behavior; hitting, pushing, shoving, kicking.

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Addressing Past Limitations

In contrast to boys, girls tend to focus more on relational ties during social interaction.

The aggressive behaviors that are most characteristic of girls tend to reflect these orientations (Crick & Grotpeter, 1995).

These types of aggressive acts have been overlooked until recently.

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Relational Aggression Includes behaviors in which damage to

relationships (or the threat of relationship damage) serves as the vehicle of harm (Crick & Grotpeter, 1995).

Includes direct and indirect acts such as threatening to end a friendship unless a peer complies with a request; using social exclusion as a retaliatory behavior; spreading rumors to encourage peers to reject a classmate.

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What’s In a Name?

A variety of other labels have been used to describe the types of behaviors I refer to as “relational aggression”

The two most common are indirect and social aggression

Both of these terms have been used to describe several types of aggressive acts, including physical aggression

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Even when the definitions of indirect and social aggression have been specifically described as “using relationships to harm others”, often the instruments used to assess these behaviors have included items without a clear focus on relationships E.g., “secretly plans to bother the other one”

(Bjorkqvist et al., 1992; Osterman et al., 1999) or “destroyed or damaged something that belonged to them” (Richardson & Green, 1999; Smith & Waterman, 2005)

In the review that this presentation is based on (Crick, 2007), only studies in which aggression was clearly assessed as harm to relationships were considered

Further, only published empirical studies were included

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What Does Relational Aggression Look Like

at Different Ages?

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Developmental Manifestations of Relational

AggressionPreschool: Ann and Susan were playing on the slide

when Tiffany came over and started talking to them. Ann and Susan covered their ears to block her out. Tiffany went to tell the teacher.

Jill and David were playing in the fantasy corner when David put on a hat that Jill wanted. They fought back and forth until Jill said “I’m not gonna be your friend”. David still wouldn’t give in so Jill said “I won’t be your BEST friend”. David gave in.

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Middle Childhood:

Say “We’re going to be in a group and you’re not going to be in it”.

Pretend you don’t see the kid. Tell a lie about them that they didn’t do. Tell your friends not to be that kid’s

friend. Say “I’m not going to be your friend

anymore”.

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Adolescence: Talk about them behind their backs and to

their face, exclude them. Pretend to be friends with them, then stab

them in the back. Tell them what you think of them in front of

their friends so they get embarrassed. Ignore them, don’t return phone calls. Try steal their boyfriend.

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Early Adulthood:

Women hurt other women by the amount of affection from men they receive. For example, saying “Mark called and he likes me better than you”.

Build up a coalition of other people against the person.

Talk about them and try to ruin their friendships with others. Gossip, gossip, gossip.

Give them the silent treatment. Act cold and bitchy.

Seduce the person’s dating partner.

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Video Example of Relational Aggression

Click HERE to view the Video

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Is Relational Aggression Really “Aggressive”?

Two Types of Evidence:1. Children’s views of the “harmful” nature

of relationally aggressive acts2. Impact of relational aggression on the

targets (i.e., relational victimization)

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Do Children View Relational Aggression as Harmful or

“Mean”?

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Children’s Reports of Mean Behavior (% of Responses)

0

10

20

30

40

50

60

PhysicalAgg

VerbalInsults

RelationalAgg

Boys

Girls

From: Crick, Bigbee, & Howes (1996)

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Does Relational Aggression Have a Negative Impact on the Frequent Targets or “Victims”?

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Relatively high levels of relational victimization have been shown to be associated with: Peer rejection (e.g., Crick, Casas, & Ku, 1997;

Cullerton-Sen & Crick, 2005; Ostrov et al., 2004; Schafer et al., 2002)

Externalizing problems (e.g., Ostrov et al., 2004) Depressive symptoms (e.g., Crick et al., 1997;

Prinstein, Boergers, & Vernberg, 2001) Loneliness (e.g., Crick & Nelson, 2002) Cigarette, alcohol, and marijuana use (Sullivan,

Farrell, & Kliewer, 2006) Obesity (Pearce, Boergers, & Prinstein, 2002) Romantic relationship and dating problems

(Pearce et al., 2002; Ruh, Crick, & Collins, 2002).

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Conclusion

According to both types of evidence, relational aggression appears to be harmful and “aggressive”!

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Are There Gender Differences in Relational Aggression?

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Mixed findings have been reported in some cases and appear to vary

according to….

Age of the participants Method used to assess relational

aggression (e.g., naturalistic observations vs. teacher reports)

Culture

A couple of examples in which gender differences have been noted….

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Percentage of Boys and Girls Classified as Aggressive

Group Boys Girls

Physically Aggressive

15.6% 0.4%

Relationally Aggressive

2.0% 17.4%

Phys & Rel Agg

9.4% 3.8%

Total 27.0% 21.6%

Physically Agg. Only

(25.0%) (4.2%)(Crick & Grotpeter, 1995)

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At What Age Can Gender Differences in Relational

Aggression First Be Identified? Naturalistic observations of relational aggression in

preschoolers (2.5 – 5 yrs. of age) have demonstrated that girls are significantly more relationally aggressive than boys during early childhood (Crick, Ostrov, Burr, Cullerton-Sen, Jansen-Yeh, & Ralston, 2006).

In this study, if relational aggression had not been assessed, we would have failed to identify 87.5% of aggressive young girls.

No studies have yet been conducted with children younger than 2.5 years.

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Does the Meaning of Relational Aggression Differ for

Boys and Girls? Preschool and school-aged girls have been

shown to feel more distress when confronted with relational conflicts and to view relationally aggressive acts as more aversive relative to boys (e.g., Coyne, Archer, & Elsea, 2006; Crick, Grotpeter, & Bigbee, 2002; Giles & Heyman, 2005)

Girls (but not boys) have been shown to exhibit greater physiological arousal (increased diastolic BP) in response to relational conflicts (Murray-Close & Crick, in press)

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Is Relational Aggression Associated with Maladaptive

Outcomes?

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Relational aggression has been shown to be associated with:

Peer Rejection (Andreou, 2006; Crick, 1996; Hennington et al., 1998; Johnson & Foster, 2007; Rys & Bear, 1997; Tomada & Schneider, 1997; Storch, Werner, & Storch, 2003; Werner & Crick, 1999; Zimmer-Gembeck et al., 2005)

Internalizing Problems such as depressive symptoms, anxiety, somatic complaints, & loneliness (e.g., Crick, 1997; Loudin, Loukas, & Robinson, 2003; Prinstein, Boergers, & Vernberg, 2001; Roach & Gross, 2003)

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And also with….

Externalizing Difficulties such as delinquent behavior, anger, # of school detentions, ADHD, psychopathy, & substance use (e.g., Crick, 1997; Marsee et al., 2005; Park et al., 2005; Prinstein et al., 2001; Roach & Gross, 2003; Storch, Werner, & Storch, 2003; Sullivan, Farrell, & Kliewer, 2006; Zahn-Waxler, 2005; Zalecki & Hinshaw, 2004)

Maladaptive Personality Characteristics such as antisocial personality features, borderline personality features, & narcissism (Crick, Murray-Close, & Woods, 2005; Marsee, Silverthorn, & Frick, 2005)

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Aspects of these associations between relational aggression and social-psychological adjustment difficulties have been demonstrated in a number of countries including:

USA Japan Greece China

Australia Italy Russia Canada

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The majority of existing studies have been cross-sectional; however, a few longitudinal studies have been conducted and these show that relational aggression predicts future maladjustment… Some example findings:

High levels of relational aggression in 3rd grade predicted low levels of social preference 3 years later in 6th grade for girls, but not boys (Zimmer-Gembeck, Geiger, & Crick, 2005)

Observed relational aggression significantly predicted future peer rejection (assessed at 6, 12, and 18 month intervals) for preschoolers (Crick et al., 2006)

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More example findings….

Increases in 4th graders’ relational aggression over an 18 mo. interval were associated with increases in internalizing symptoms (Murray-Close, Ostrov, & Crick, in press) and also increases in borderline personality features (Crick, Murray-Close, & Woods, 2005)

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Relational vs. Physical Aggression and Maladjustment

Relational aggression provides unique information about maladjustment, above and beyond that provided by physical aggression, primarily for girls.

Physical aggression tells most of the story about aggression and adjustment problems for boys whereas relational aggression tells most of the story for girls.

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What are Some Factors that Might Contribute to the Development

and/or Maintenance of Relationally Aggressive Behavior Patterns?

HeritabilitySocialization via relationshipsSocial cognitive patterns

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Is Relational Aggression Heritable?

A behavior genetic study (Brendgen, Dionne, Girard, Boivin, Vitaro, & Perusse, 2005) of 6-year-old twins showed that: 63% of the variation in teacher’s ratings of

physical aggression was accounted for by genetic effects

In contrast, only 20% of the variation in relational aggression was accounted for by genetic effects

These findings suggest the particular importance of examining environmental influences on relational aggression.

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The Relationships of Relationally Aggressive Youth

ParentsSiblingsFriendsAntipathiesRomantic Partners

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Parenting characteristics shown to be associated with relational aggression include: Authoritarian parenting styles (Casas et al.,

2006) Permissive parenting styles (Casas et al.,

2006) Physical coercion (Hart et al., 1998; Nelson et

al., 2006) Lack of paternal responsiveness (Hart et al.,

1998) Psychological control strategies (Casas et al.,

2006; Nelson et al., 2006)

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And also....

Insecure attachment behaviors (Casas et al., 2006)

Lack of paternal involvement (i.e., time spent with fathers; Updegraff et al., 2005)

Lack of parental warmth (Updegraff et al., 2005)

Lack of concern regarding children’s use of relational aggression (Ohan & Johnston, 2005; Werner et al., 2006)

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A few caveats

Most studies targeted preschoolers Some findings may be moderated by

gender of parent and/or gender of child Studies were conducted in several

countries

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Sibling Relationships

Stauffacher & DeHart (2005; 2006) observed acts of relational aggression during 15-20 minute play sessions between 4-year-old children and their siblings and friends (follow-up conducted at 8 years of age).

Results: RA more frequent in sibling than friend

interactions at 4 years of age From 4 to 8 years, RA decreased in sibling

dyads but increased in friend dyads

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Siblings Cont’d

Older siblings’ use of peer-directed relational aggression predicted increases in younger siblings’ use of RA over the course of a school year during preschool (Ostrov et al., 2006). Socialization?

Adolescents’ use of RA within the sibling dyad has been shown to be associated with a lack of intimacy and relatively high levels of negativity within the sibling relationship (Updegraff et al., 2005).

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Friendships: Having Friends

Few published studies and findings are mixed Some studies show relational aggression to

be associated with having fewer friends compared with peers (e.g., Johnson & Foster, 2005; Sebanc, 2003) whereas others find RA to be related to having more or the same # of friends (e.g., Burr et al., 2005; Rys & Bear, 1997)

Overall, findings suggest that gender of the child or dyad may serve as a moderator

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Friendships: Quality of the Relationship

Relational aggression has been shown to be associated with: Jealousy/feelings of exclusivity (Grotpeter & Crick,

1996; Sebanc, 2003) High levels of intimacy (Grotpeter & Crick, 1996;

Sebanc, 2003) Use of relational aggression within friend

interactions (Grotpeter & Crick, 1996) Conflict (Cillessen et al., 2005; Sebanc, 2003)

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Friendship: Characteristics of the Friend

Friends’ tend to exhibit similar levels of relational aggression - this association is stronger for reciprocal than for unilateral friends (Cillessen et al., 2005; Werner & Crick, 2004)

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Is it Problematic to Befriend a Relationally Aggressive Child?

Nonaggressive 3rd grade girls who are best friends with relationally aggressive girls become significantly more relationally aggressive themselves a year later in 4th grade (Werner & Crick, 2004)

Peers may serve as an important socializing force.

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Antipathies

What is an antipathy? Two children who identify each other as a

“disliked peer” (Abecassis et al., 2002) Results of a longitudinal study show that

increases over time in both same- and opposite-sex antipathies are associated with increases in relational aggression for girls, but not for boys (Murray-Close & Crick, in press)

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Romantic Relationships Do girls use RA to damage the reputations of

their dating rivals? Results of a longitudinal study show that increases

in dating popularity are associated with increases in relational aggression for adolescent girls, but not for boys (Pellegrini & Long, 2003).

Does RA exhibited toward romantic partners affect the quality of that relationship? Romantic partner RA has been shown to be

associated with negative relationship qualities such as jealousy, lack of trust, frustration, anxious clinging to the romantic partner, and ambivalence about the relationship (Linder, Crick, & Collins, 2002)

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Social-Information-Processing Patterns Associated with

Relational Aggression

Intent AttributionsAre peers acting with benign or hostile intent in ambiguous conflict situations?

52Crick & Dodge (1994). Psychological Bulletin

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Instrumental Conflicts Imagine that you are walking to school and you

are wearing your new tennis shoes. You really like your new shoes and this is the first day that you have worn them. Suddenly, you are bumped from behind by another kid. You stumble and fall into a mud puddle and your new shoes get muddy.

Why did the kid bump into you? Hostile intent (hostile attribution bias) = “S/he wanted

to me to ruin my new shoes”; “S/he wanted to get even with me for something”

Benign intent = “S/he tripped over a rock in the road and then fell into me”

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Findings show that….

Physically aggressive children exhibit hostile attributional biases for instrumental conflicts (Crick, 1995; Crick, Grotpeter, & Bigbee, 2002).

Relationally aggressive children do NOT.

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Relational Conflicts Imagine that you are in the bathroom one day

after recess. While you are in there, two other kids from your class come in and start talking to each other. Your hear one of the kids invite the other one to a birthday party. The kid says that there are going to be a lot of people at the party. You have not been invited to the party.

Why haven’t you been invited to the party? Hostile Intent (hostile attribution bias) = “The kid

doesn’t want me to come to the party”; “The kid is mad at me about something”

Benign Intent = “The kids hasn’t had a chance to ask me yet”; “My invitation is at home in my mailbox”

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Findings show that:

Relationally aggressive children exhibit hostile attributional biases for relational conflicts (Crick, 1995; Crick, Grotpeter, & Bigbee, 2002).

Physically aggressive children do NOT.

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General Conclusions

Contrary to existing theories, girls exhibit significant aggressive behavior problems prior to adolescence.

Similar to physical aggression, relational aggression is associated with significant adjustment difficulties.

Relational aggression is particularly important for understanding the difficulties of girls.

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Environmental factors seem to be particularly important for the development of relational aggression

Parents, friends, and siblings may play a socializing role.

Social- information-processing patterns may contribute to children’s use of relational aggression.

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Acknowledgments

National Institute of Mental Health National Institute of Child Health and Human

Development National Science Foundation William T. Grant Foundation Harry F. Guggenheim Foundation Special thanks to the graduate and

undergraduate research assistants as well as the study participants who made this research possible.