اثرات جنسیتی در زورگویی:نتایج از یک نمونه ملی

Abstract This study presents gender effects in sociodemographics and psychiatric correlates of bullying in the United States. Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a nationally representative sample of U.S. adults. Face-to-face interviews of more than 43,000 adults were conducted during the 2001–2002 period. The present study compared 2460 respondents who ever bullied with 39,501 respondents who did not, stratified by gender. The prevalence of this behavior in the U.S. was significantly higher in men (8.5%) than in women (4.2%). Multivariate logistic regression analyses indicated strong associations in both genders with numerous psychiatric and addictive disorders with significant gender effects. Following adjustments for sociodemographic characteristics and other antisocial behaviors, women who ever bullied were significantly more likely to have any lifetime externalizing, including conduct disorder, as well as any lifetime internalizing spectrum disorder compared to men with such behavior. Bullying in women may be a symptom of a broader syndrome than in men, including more prevalent impairment of impulse control and more frequent affective disorders.

1. Introduction Bullying is a pattern of aggression in which the behavior is intended to harm, intimidate or disturb (Boulton and Underwood, 1992), occurs repeatedly over time (Olweus, 1978), and involves an imbalance of power, with a more powerful person or group attacking a less powerful one (Salmivalli et al., 1999). Bullying often begins in childhood, affecting approximately 30% of youth in the U.S. (Nansel et al., 2001). This behavior can take many forms, including verbal (e.g., name-calling), physical (e.g., hitting), or psychological bullying (e.g., rumors, social exclusion) (Nansel et al., 2001). Longitudinal studies highlight emotional consequences for youth who are bullied (Bond et al., 2001). Victims of bullying report higher levels of insecurity (Glew et al., 2008), lower self-esteem (Glew et al., 2008), higher rates of loneliness (Eslea et al., 2003), anxiety, depression and suicidal ideations (Kaltiala-Heino et al., 1999, Bond et al., 2001 and Sourander et al., 2007). They are also more likely to have academic problems (Glew et al., 2008), adverse physical health symptoms, and to report lower levels of social adjustment when compared to the general population (Rigby, 2003). With growing concern about the detrimental consequences of bullying, recent studies have focused on characterizing bullies themselves to further strengthen prevention efforts. One national study found that 19.3% of youth in the U.S. reported bullying others (Nansel et al., 2001). Bullying is more frequent among boys than girls (Luukkonen et al., 2010). Approximately every fifth boy has bullied at school, whereas this behavior occurs only once in every ten girls. Bullying behavior during childhood is associated with conduct disorder and hyperactivity attention deficit disorder and oppositional defiant disorder (Kumpulainen et al., 1999 and Kumpulainen et al., 2001). In addition, youth who bully others are more likely to present paranoid, histrionic and passive–aggressive personality traits (Coolidge et al., 2004), as well as depression (Kaltiala-Heino et al., 1999) and suicide attempts (Klomek et al., 2010). Bullying typically begins in childhood or adolescence (Carney and Merrell, 2001), but this behavior can persist into adulthood as a continuing pattern of antisocial behavior (Kim et al., 2011 and Renda et al., 2011), with long-term social and psychological consequences (Sourander et al., 2007 and White and Loeber, 2008). These findings support that bullying behavior in childhood or adolescence is prevalent and associated with numerous externalizing as well as internalizing spectrum disorders, rejecting the widespread idea that school bullying is a natural part of growing up. In addition, this behavior may be influenced by different non-exclusive environmental factors, including peer norms and media messages that can promote the idea that bullying is “no big deal”, school's culture and family dynamics (how family members relate to one another) (Horne et al., 2000), as well as possible biological factors (Compton et al., 2007 and Hasin et al., 2007).

3. Results 3.1. Prevalence and sociodemographic correlates (Table 1) Table 1 provides comparisons of participants who ever bullied to those who never did across sociodemographic characteristics, stratified by gender. The overall lifetime prevalence rates of respondents who ever bullied in the U.S. population were 8.5% in men and 4.2% in women. The odds of bullying were significantly higher in men than in women (odds ratio=1.94, 95% CI=1.78–2.11). In both genders, Asian/Native Hawaiian/Pacific Islander Americans had lower odds of bullying than Whites. Being U.S.-born, in the youngest group of age (18–29 yr), having a high school level of education, being divorced/separated or widowed and living in the West region of the U.S. increased the risk of bullying in both genders. Men and women having some college or higher education were significantly less likely to ever bully others. In addition, bullying was significantly more common in women never married or living in the Midwest region. There were no significant differences with respect to household income and urbanicity in any gender. Table 1. Sociodemographic characteristics of participants who ever bullied, by gender. Characteristic Male Female Bullying (N=1434)% a Non-bullying (N=16,551)% a Odds ratiob (95% CI) Bullying (N=1026)% a Non-bullying (N=22,950)% a Odds ratiob (95% CI) Race/ethnicity White 72.3 71.2 1.00 (1.00–1.00) 67.9 70.8 1.00 (1.00–1.00) Black 9.8 10.1 0.89 (0.77–1.03) 14.9 11.7 1.15 (0.98–1.36) American Indian/Alaska native 4.2 1.8 0.99 (0.82–1.19) 4.0 2.0 0.90 (0.74–1.08) Asian/Native Hawaiian/Pacific Islander 3.0 4.6 0.41 (0.30–0.58) 2.1 4.5 0.50 (0.34–0.74) Hispanic 10.7 12.3 1.32 (0.91–1.92) 11.1 10.9 1.42 (0.91–2.20) Nativity Born in the United States 92.2 84.3 1.95 (1.64–2.32) 92.7 85.5 2.06 (1.66–2.56) Born in a foreign country 7.8 15.7 1.00 (1.00–1.00) 7.3 14.5 1.00 (1.00–1.00) Age (years) 18–29 31.8 22.0 1.00 (1.00–1.00) 41.0 20.2 1.00 (1.00–1.00) 30–44 37.1 31.0 0.21 (0.16–0.27) 35.2 29.9 0.11 (0.09–0.15) 45–64 27.0 31.8 0.25 (0.20–0.32) 19.1 31.2 0.20 (0.15–0.27) 65+ 4.1 15.2 0.35 (0.27–0.45) 4.7 18.6 0.31 (0.23–0.42) Education Less than high school 3.5 6.5 1.00 (1.00–1.00) 3.1 6.1 1.00 (1.00–1.00) High school graduate 47.5 37.4 2.07 (1.55–2.77) 47.5 38.8 2.03 (1.45–2.85) Some college or higher 49.0 56.1 0.74 (0.67–0.83) 49.3 55.1 0.78 (0.69–0.89) Marital status Married/cohabiting 59.7 65.2 1.00 (1.00–1.00) 51.4 59.8 1.00 (1.00–1.00) Widowed 0.4 2.6 1.30 (1.15–1.47) 3.6 10.5 1.80 (1.56–2.09) Divorced/separated 12.0 9.0 5.16 (3.06–8.68) 14.7 12.2 4.65 (3.45–6.27) Never married 27.9 23.2 1.01 (0.86–1.20) 30.3 17.5 1.32 (1.10–1.57) Household income ($) 0–19,999 19.7 16.5 1.09 (0.93–1.29) 27.1 25.4 0.86 (0.73–1.02) 20,000–34,999 19.3 19.9 0.92 (0.79–1.07) 23.3 19.8 1.18 (0.99–1.41) 35,000–59,999 30.6 27.3 1.16 (0.99–1.36) 22.2 24.6 1.12 (0.94–1.34) 60,000 or greater 30.4 36.0 1.00 (1.00–1.00) 27.5 30.1 1.00 (1.00–1.00) Urbanicity Urban 29.9 29.1 1.00 (1.00–1.00) 30.4 29.6 1.00 (1.00–1.00) Rural 70.1 70.9 0.94 (0.84–1.05) 69.6 70.4 0.92 (0.81–1.05) Region Northeast 17.0 19.9 1.00 (1.00–1.00) 17.6 19.9 1.00 (1.00–1.00) Midwest 27.6 22.9 1.18 (0.99–1.39) 31.2 22.7 1.27 (1.04–1.54) South 30.9 35.3 0.91 (0.78–1.06) 28.9 35.6 0.88 (0.74–1.05) West 24.5 22.0 1.32 (1.14–1.52) 22.2 21.8 1.37 (1.16–1.62) a Percentages are weighted values. b CI confidence interval, OR odds ratios adjusted for sociodemographic variables. OR values in bold are statistically significant (p<0.05). Table options 3.2. Bullying and associated antisocial behaviors (Table 2) Table 2 indicates convergent relations between antisocial behaviors in participants who reported or not having ever bullied others, stratified by gender. Since the prevalence of the majority of antisocial behaviors was substantially higher among men who ever bullied than among women, we controlled for the effect of other lifetime antisocial behaviors. Table 2. Convergent relations between antisocial behaviors in participants who ever bullied, by gender. Behavior Male Female Interaction between gender and antisocial behavior Bullying (N=1434)% a Non-bullying (N=16,551)% a Adjusted odds ratiob (95% CI) Bullying (N=1026)% a Non-bullying (N=22,950)% a Adjusted odds ratiob (95% CI) Odds ratioc (95% CI) P value c Cut class and leave without permission 60.5 23.4 1.81 (1.57–2.10) 52.4 16.2 2.12 (1.79–2.50) 0.83 (0.70–0.98) 0.03 Stay out late at night 65.3 27.8 2.17 (1.88–2.50) 55.1 19.5 2.22 (1.89–2.60) 0.93 (0.78–1.10) 0.41 Run away from home overnight 16.5 4.1 1.11 (0.89–1.38) 23.7 4.3 1.29 (1.04–1.60) 0.72 (0.58–0.90) <0.01 Be absent from school a lot 26.6 6.0 1.20 (0.99–1.45) 25.3 5.3 0.99 (0.80–1.22) 0.87 (0.71–1.07) 0.18 Quit a school program without knowing what to do next 14.6 3.6 1.26 (1.01–1.58) 12.3 2.7 0.98 (0.75–1.29) 0.98 (0.76–1.27) 0.89 Hurt an animal on purpose 12.9 2.3 1.66 (1.29–2.12) 2.7 0.5 1.91 (1.16–3.14) 0.93 (0.61–1.42) 0.75 Lie a lot 22.8 4.4 1.33 (1.09–1.62) 24.6 3.8 1.30 (1.04–1.63) 0.82 (0.66–1.02) 0.07 Destroy others' property 25.1 4.3 1.13 (0.92–1.40) 12.7 1.2 1.14 (0.82–1.59) 0.68 (0.52–0.89) <0.01 Quit a job without knowing where to find another 33.5 11.8 1.06 (0.90–1.25) 33.4 8.7 1.53 (1.28–1.85) 0.74 (0.62–0.89) <0.01 Travel around more than one month without plans 13.0 4.2 1.32 (1.01–1.73) 10.0 1.7 1.10 (0.78–1.55) 0.56 (0.42–0.74) <0.01 Have no regular place to live at least one month 11.2 2.9 1.63 (1.20–2.22) 8.9 1.7 1.70 (1.18–2.44) 0.70 (0.51–0.95) 0.02 Live with others at least one month 31.1 10.6 1.41 (1.18–1.67) 30.0 9.3 1.33 (1.10–1.61) 0.89 (0.74–1.07) 0.20 Use a false or made-up name/alias 10.2 1.9 1.18 (0.89–1.57) 10.3 1.3 1.16 (0.85–1.60) 0.72 (0.53–0.96) 0.03 Scam/con someone for money 12.6 1.2 1.92 (1.43–2.58) 8.6 0.6 1.20 (0.79–1.82) 0.74 (0.53–1.04) 0.09 Do things that could have easily hurt you/others 48.8 18.0 1.30 (1.12–1.51) 26.0 7.4 1.43 (1.17–1.76) 0.95 (0.79–1.15) 0.62 Get three or more traffic tickets for reckless driving/causing accidents 29.4 12.4 1.26 (1.07–1.49) 11.1 3.7 1.13 (0.86–1.48) 0.89 (0.70–1.13) 0.33 Have driver's license suspended/revoked 28.8 11.3 1.18 (1.01–1.40) 10.7 2.9 0.98 (0.74–1.30) 0.74 (0.58–0.95) 0.02 Fail to pay off your debts 15.9 4.1 0.92 (0.73–1.16) 15.3 2.9 1.22 (0.94–1.58) 0.77 (0.60–0.98) 0.03 Steal anything from others 37.9 9.5 1.56 (1.30–1.86) 29.6 5.3 1.79 (1.44–2.24) 0.82 (0.68–0.99) 0.04 Forge someone's signature 8.1 1.7 1.08 (0.80–1.47) 11.1 1.7 1.21 (0.88–1.66) 0.80 (0.58–1.10) 0.16 Set a fire on purpose 8.3 1.4 1.18 (0.84–1.64) 2.2 0.3 0.91 (0.50–1.65) 0.76 (0.46–1.26) 0.29 Ever shoplift 38.9 11.8 1.17 (0.98–1.39) 33.5 7.8 1.25 (1.01–1.55) 0.80 (0.67–0.96) 0.02 Rob/mug someone or snatch a purse 3.1 0.3 0.85 (0.50–1.43) 1.0 0.1 0.48 (0.17–1.36) 0.83 (0.36–1.88) 0.65 Make money illegally 16.9 3.4 1.77 (1.38–2.27) 9.1 0.8 1.24 (0.84–1.84) 0.53 (0.39–0.72) <0.01 Do something you could have been arrested for 56.0 19.3 1.31 (1.12–1.55) 34.7 8.1 0.89 (0.71–1.11) 0.89 (0.74–1.06) 0.20 Force someone to have sex 0.9 0.1 2.39 (0.99–5.78) 0.4 0.1 0.78 (0.22–2.76) 1.35 (0.45–4.05) 0.59 Get into lots of fights that you started 27.1 1.8 5.58 (4.56–6.83) 22.1 0.9 6.35 (4.91–8.22) 0.70 (0.54–0.90) <0.01 Get into a fight that came to swapping blows with others 17.8 4.7 1.24 (1.02–1.52) 31.2 6.3 1.35 (1.11–1.64) 0.69 (0.56–0.85) <0.01 Use a weapon in a fight 17.5 2.6 1.08 (0.85–1.37) 11.5 1.2 1.19 (0.87–1.64) 0.71 (0.55–0.93) 0.01 Hit someone so hard that you injure them 36.3 7.7 1.67 (1.41–1.98) 17.5 1.6 1.65 (1.25–2.18) 0.63 (0.50–0.79) <0.01 Harass/threaten/blackmail someone 14.2 1.0 2.19 (1.63–2.94) 15.9 0.7 2.91 (2.11–4.01) 0.65 (0.47–0.89) <0.01 Physically hurt others on purpose 27.8 5.6 1.71 (1.43–2.05) 20.4 2.1 1.72 (1.33–2.22) 0.64 (0.51–0.80) <0.01 a Percentages are weighted values. b OR odds ratios adjusted for other antisocial behaviors. OR values in bold are statistically significant (p<0.05). c OR odds ratios examining interaction between gender and other antisocial behaviors. OR values in bold are statistically significant (p<0.05). Table options Following adjustments, odds ratios were higher among women for 10 of the 13 antisocial behaviors that were significantly associated with bullying in any gender. Moreover, seven behaviors were significantly associated with bullying in men, whereas they were not in women (namely quitting a school program without knowing what to do next, traveling around more than one month without plans, scamming someone for money, getting three or more traffic tickets for reckless driving/causing accidents, having driver's license suspended, making money illegally, and doing illegal things). At variance, three behaviors were significantly associated with bullying in women whereas they were not in men (namely running away from home overnight, quitting a job without knowing where to find another and shoplifting). Odds ratios examining the interaction between gender and other antisocial behaviors indicated that 18 out of 32 antisocial behaviors were significantly more associated with bullying in women than in men. No antisocial behavior was significantly more associated with bullying in men than in women. 3.3. Lifetime internalizing spectrum disorders (Table 3) Table 3 compares prevalence rates of lifetime internalizing spectrum disorders in participants who reported or not having ever bullied others, stratified by gender. Table 3. Gender differences in lifetime internalizing spectrum disorders in participants who ever bullied. Comorbid psychiatric disorder Male Female Interaction between gender and psychiatric disorder Bullying (N=1434)% a Non-bullying (N=16,551)% a Adjusted odds ratiob (95% CI) Bullying (N=1026)% a Non-Bullying (N=22,950)% a Adjusted odds ratiob (95% CI) Adjusted odds ratioc(95% CI) P value c Internalizing spectrum disorders 45.0 20.6 1.31 (1.14–1.52) 63.1 33.4 1.64 (1.41–1.92) 0.79 (0.65–0.96) 0.02 Mood Disorders 34.7 13.7 1.37 (1.17–1.60) 50.2 22.9 1.49 (1.27–1.74) 0.89 (0.72–1.09) 0.25 Major depressive disorder 24.3 10.9 1.23 (1.04–1.45) 43.1 20.3 1.31 (1.12–1.54) 0.90 (0.72–1.12) 0.34 Bipolar disorder 18.8 4.6 1.59 (1.30–1.94) 23.0 5.0 1.58 (1.28–1.94) 0.94 (0.72–1.24) 0.67 Dysthymia 7.4 2.7 0.99 (0.73–1.33) 14.8 5.2 1.26 (0.99–1.61) 0.75 (0.51–1.08) 0.12 Anxiety disorders 25.9 11.7 1.14 (0.97–1.35) 39.6 21.1 1.39 (1.19–1.63) 0.82 (0.66–1.02) 0.07 Panic disorder 9.2 2.8 1.43 (1.09–1.87) 14.5 6.5 1.15 (0.91–1.44) 1.19 (0.85–1.69) 0.32 Social phobia 8.7 3.9 1.08 (0.83–1.40) 13.1 5.5 1.38 (1.09–1.75) 0.77 (0.54–1.08) 0.13 Specific phobia 13.3 5.7 1.05 (0.84–1.31) 23.5 12.1 1.22 (1.01–1.46) 0.85 (0.64–1.13) 0.26 Generalized anxiety disorder 7.3 2.5 1.25 (0.93–1.67) 13.4 5.1 1.31 (1.03–1.67) 0.91 (0.63–1.32) 0.62 a Percentages are weighted values. b OR Odds ratios adjusted for sociodemographic characteristics and other antisocial behaviors. c Odds ratios examining the interaction between gender and comorbid psychiatric disorder adjusted for sociodemographic characteristics and other antisocial behaviors. OR values in bold are statistically significant (p<0.05). Table options Following adjustments for sociodemographic characteristics and other antisocial behaviors, women who ever bullied were significantly more likely than their counterparts to have all lifetime internalizing spectrum disorders except from dysthymia and panic disorder. Men who ever bullied had significantly higher rates of any lifetime internalizing spectrum disorder, including mood disorders (e.g. major depressive disorder and bipolar disorder), and panic disorder. In addition, men who ever bullied were significantly less likely to have any lifetime internalizing spectrum disorder than women who ever bullied (AOR=0.79, 95% CI=0.65–0.96), while controlling for sociodemographic characteristics and other antisocial behaviors. 3.4. Lifetime externalizing spectrum disorders (Table 4) Table 4 indicates prevalence rates of lifetime externalizing spectrum disorders in respondents reporting or not having ever bullied others, stratified by gender. Following adjustments for sociodemographic characteristics and other antisocial behaviors, women who ever bullied were significantly more likely than their counterparts to have any lifetime externalizing spectrum disorder, including substance use disorders (e.g. alcohol abuse and nicotine dependence), conduct disorder, and antisocial personality disorder, and they were less likely to report amphetamine, hallucinogen, cocaine, opioid, sedative and tranquilizer use disorders. Men who ever bullied had significantly higher rates of substance use disorders, including alcohol abuse and dependence, conduct disorder and antisocial personality disorder than their counterparts, while controlling for sociodemographic characteristics and other antisocial behaviors. Table 4. Gender differences in lifetime externalizing spectrum disorders in participants who ever bullied. Comorbid psychiatric disorder Male Female Interaction between gender and psychiatric disorder Bullying (N=1434)% a Non-bullying (N=16,551)% a Adjusted odds ratiob (95% CI) Bullying (N=1026)% a Non-bullying (N=22,950)% a Adjusted odds ratiob (95% CI) Adjusted odds ratioc (95% CI) P value c Externalizing spectrum disorders 39.8 28.1 1.00 (0.87–1.15) 45.6 29.7 1.30 (1.12–1.51) 0.76 (0.63–0.93) <0.01 Substance use disorders 78.9 46.2 1.48 (1.26–1.74) 63.3 27.6 1.29 (1.08–1.53) 1.11 (0.90–1.36) 0.32 Alcohol use disorders 70.6 39.5 1.42 (1.22–1.66) 47.5 18.4 1.21 (1.01–1.44) 1.13 (0.92–1.38) 0.24 Alcohol abuse 30.8 24.2 1.18 (1.02–1.36) 22.7 11.1 1.26 (1.04–1.52) 0.96 (0.76–1.21) 0.74 Alcohol dependence 39.9 15.3 1.18 (1.01–1.38) 24.8 7.3 0.98 (0.79–1.21) 1.11 (0.88–1.40) 0.40 Nicotine dependence 41.0 18.3 1.05 (0.90–1.22) 41.1 14.7 1.22 (1.02–1.45) 0.86 (0.69–1.06) 0.15 Drug use disorders 36.2 11.9 1.01 (0.85–1.20) 27.6 6.3 0.86 (0.68–1.08) 1.04 (0.82–1.32) 0.74 Cannabis 31.3 10.1 0.98 (0.82–1.17) 23.0 4.7 1.03 (0.82–1.30) 0.90 (0.70–1.16) 0.42 Amphetamine 9.2 1.9 0.88 (0.64–1.21) 6.9 1.3 0.59 (0.39–0.90) 1.25 (0.78–1.99) 0.36 Hallucinogen 9.8 1.8 0.78 (0.57–1.07) 5.0 0.8 0.45 (0.27–0.73) 1.45 (0.85–2.46) 0.18 Cocaine 12.3 3.2 0.85 (0.65–1.10) 7.3 1.5 0.53 (0.36–0.77) 1.32 (0.89–1.96) 0.18 Heroin 1.5 0.2 0.93 (0.46–1.88) 0.9 0.1 0.62 (0.20–1.88) 1.40 (0.40–4.86) 0.60 Opioid 7.7 1.5 0.88 (0.63–1.24) 4.3 0.7 0.58 (0.35–0.97) 1.26 (0.71–2.24) 0.42 Sedative 6.6 1.2 0.94 (0.65–1.36) 2.9 0.5 0.30 (0.16–0.55) 2.46 (1.27–4.75) <0.01 Tranquilizer 5.4 1.1 0.85 (0.57–1.25) 2.9 0.4 0.40 (0.22–0.73) 1.69 (0.87–3.29) 0.12 Inhalant 2.5 0.3 0.79 (0.45–1.40) 0.9 0.1 0.95 (0.36–2.51) 0.73 (0.25–2.11) 0.56 Conduct disorder 6.6 1.1 3.99 (2.95–5.40) 7.7 0.4 8.64 (5.98–12.49) 0.47 (0.30–0.75) <0.01 Pathological gambling 2.3 0.5 1.32 (0.78–2.23) 1.3 0.2 0.90 (0.42–1.95) 1.36 (0.54–3.39) 0.51 Antisocial personality disorder 33.4 3.1 1.92 (1.55–2.38) 22.2 1.0 2.10 (1.58–2.80) 0.80 (0.60–1.08) 0.14 Suicide attempt 12.0 5.5 0.82 (0.57–1.19) 21.9 7.0 1.20 (0.91–1.59) 0.66 (0.43–1.02) 0.06 Family history of antisocial behavior 39.8 28.1 1.00 (0.87–1.15) 45.6 29.7 1.30 (1.12–1.51) 0.76 (0.63–0.93) <0.01 a Percentages are weighted values. b OR Odds ratios adjusted for sociodemographic characteristics and other antisocial behaviors. c Odds ratios examining the interaction between gender and comorbid psychiatric disorder adjusted for sociodemographic characteristics and other antisocial behaviors. OR values in bold are statistically significant (p<0.05). Table options Odds ratios examining interactions between gender and lifetime psychiatric disorders, controlling for sociodemographic characteristics and other antisocial behaviors, indicated that men who ever bullied were significantly less likely than women who ever bullied to have any lifetime externalizing spectrum disorder (AOR=0.76, 95% CI=0.63–0.93), including conduct disorder (AOR=0.47, 95% CI=0.30–0.75), and more likely to report a sedative use disorder (AOR=2.46, 95% CI=1.27–4.75). In addition, men who ever bullied were significantly less likely than women with such history to have a family history of antisocial behavior (AOR=0.76, 95% CI=0.63–0.93). There was no significant gender effect in suicide attempt.