Is the curve relating temperature to aggression linear or curvilinear? A response to Bell (2005) and to Cohn and Rotton (2005)

P. Bell recommended examining the relationship between temperature and assaults during the hottest times of day and during the hottest months of the year. The authors' analyses of these data show a linear rather than inverted U-shaped relationship between temperature and assault during the hottest times of day and in the hottest months of the year. E. Cohn and J. Rotton recommended analyzing the 6 hr with the highest assaults versus the 6 hr with the lowest assaults. During high assault periods, there is a strong positive linear relationship between temperature and assault. During low assault periods, there is no relationship between temperature and assaults. Assaults and other violent crimes might decrease when temperatures are very hot, but the Minneapolis data set does not allow for testing of this hypothesis because Minneapolis is too cold.     

Violent Movies and Severe Acts of Violence: Sensationalism Versus Science

Violent media has often been blamed for severe violent acts. Following recent findings that violence in movies has increased substantially over the last few decades, this research examined whether such increases were related to trends in severe acts of violence. Annual rates of movie violence and gun violence in movies were compared to homicide and aggravated assault rates between the years of 1960 and 2012. Time series analyses found that violent films were negatively, although nonsignificantly, related to homicides and aggravated assaults. These nonsignificant negative relations remained present even after controlling for various extraneous variables. Results suggest that caution is warranted when generalizing violent media research, conducted primarily in laboratories and via questionnaires, to societal trends in violent behavior.     

Changes in ambulance departures for assault calls during COVID-19 pandemic restrictions

Restrictions related to COVID-19 changed the daily behavior of people, including the expression of violence. Although an increased incidence of violent behavior, especially domestic violence, was expected during the pandemic, retrospective analyses have yielded mixed results. Records of ambulance departures to address injuries caused by assaults in the Pilsen region, Czech Republic, during the restrictive measures during the national state of emergency were compared to data from 3 previous years using general linear models. The number and severity of assaults were analyzed for the whole sample and separately for patients of either sex, for residential or nonresidential locations, and for domestic violence. Controlling for the seasonal effects, the number of assaults decreased by 39% during the pandemic restrictions compared to the 3 previous years. No difference was found between the effects of restrictions on assaults resulting in an injury of a male or female patient. The decrease was specifically pronounced in the sample of assaults in nonresidential locations, while no effect of restrictions was observed in assaults in residential locations and domestic assaults. Pandemic restrictions were associated with a decreased incidence of violent assaults that required ambulance services. Although the incidence decreased especially in those assaulted outside of their homes, we found no support for an increase in domestic violence or violence against women. Pandemic restrictions may have served as a protective rather than a risk factor for assaults severe enough to warrant a call for ambulance services.     

Heat and Violence: New Findings from Dallas Field Data, 1980–19811

Research in both laboratory and field settings has suggested a link between thermal stress and violent behavior, and both linear and curvilinear models have been investigated. A dearth of field studies prompted the analysis reported here, which is based on data for some 10,000 aggravated assaults occurring the City of Dallas in 1980 (a summer of severe heat stress) and 1981. This analysis replicates and extends certain aspects of recent work by Anderson and Anderson (1984) relating to the so-called linear and curvilinear hypotheses. Thermal stress is measured in two ways: a Discomfort Index (DI), which takes into account the influence of humidity acting in concert with temperature, and ambient temperature. Regression analyses were performed in two stages. In the first, data for all neighborhoods and all days of the study period were combined into ambient temperature and DI models. At the second stage, models differentiated between the three levels of neighborhood socioeconomic status. With weekend controlled, DI and ambient temperature were significant independent variables in the ‘overall’ model and in medium and low status neighborhoods. However, when linear effects were controlled, the curvilinear measures were never significant. The analysis generally tended to confirm Anderson and Anderson's suggestion that a reduction of aggression with increasing temperature does not appear to occur within the normal range of temperatures. This analysis further suggested that the hypothesized curvilinear effect is weak, if not entirely absent, even during conditions of extreme heat.     

Why is violent crime so common in the Americas?

Violent crimes, including murders, rapes, and assaults are substantially higher in the Americas than other regions of the world. This study investigated the role of single parenthood ratios in accounting for this regional variation in violent crime of 39 countries using INTERPOL data. It pitted the prediction of parental investment (calling for a delayed relationship between single parenthood and crime) against a mating aggression hypothesis that predicted a contemporaneous effect. Regression analyses found that current single parenthood ratios were strongly and consistently predictive of violent crimes whereas single parenthood ratios 18 years earlier were not and this conclusion remained following controls for income inequality and the population sex ratio. The results indicate that the regional difference in violent crime is best explained in terms of mating competition rather than reduced parental investment. Aggr. Behav. 32:1–9, 2006. © 2006 Wiley‐Liss, Inc.     

A COMPARISON OF GROUP AND INDIVIDUAL SEXUAL ASSAULT VICTIMS

The experiences of 44 group sexual assault victims (multiple offenders, one victim) were compared with 44 individual sexual assault victims (one offender, one victim). Sexual assaults included various degrees of sexual victimization ranging from verbal coercion to rape. Participants were located from among a national sample of 3,187 college women. Group sexual assaults, compared to individual sexual assaults, were in general more violent, involved greater resistance from the victims, and were more likely to be perpetrated by strangers or relatives and to involve an experience which met the legal definition of rape. Group sexual assaults were less likely to involve multiple episodes by the same offender(s). Group sexual assault victims were more likely than individual sexual assault victims to seek police and crisis services, to have contemplated suicide, and to have sought therapy postassault. Despite these differences, the two groups were similar in the amount of drinking and drug use during the assault and their scores on standardized measures of psychological symptoms.     

Impact of Exposure to Community Violence on Anxiety: A Longitudinal Study of Family Social Support as a Protective Factor for Urban Children

In a longitudinal study, we examined the relationship between exposure to community violence and anxiety, and the extent to which family social support moderated this relationship within a predominantly African American sample of 385 children in an urban public school system. Children reported notably lower anxiety levels compared to normative data for African American children. A high percentage reported witnessing a variety of violent acts. Cross-sectional results indicated that among girls exposure to violence was significantly correlated with total, physiological, and concentration anxiety. Among boys violence exposure was not associated with anxiety. Hierarchical regression analyses indicated that after controlling for gender, exposure to violence at Time 1 did not significantly predict changes in anxiety. A significant interaction was found for gender and exposure to violence on concentration anxiety; girls who reported higher initial violence exposure reported greater increases in subsequent concentration anxiety than boys. Whereas findings from our study did not support a moderating relationship of family social support on children's exposure to violence and anxiety, a strong negative relationship was found between anxiety and family support. Among children with initially low worry anxiety, those with low family social support showed greater increases in subsequent worry anxiety.     

Testosterone,aggressiveness, and antisocial personality

Testosterone levels were examined in prisoners convicted of violent crimes (n = 13), in men previously convicted of violent crimes but currently not in prison (n = 15), in nonviolent alcoholics (n = 15), and in randomly selected control males (n = 16). Morning, afternoon, and evening testosterone levels were assessed after a minimum alcohol abstinence period of 24 hr. Violent and nonviolent men did not differ in plasma total testosterone level on any sampling occasion. In violent men, however, testosterone levels were significantly correlated with hostility, as measured by the Derogatis Symptom Check List. Most violent men were diagnosed with Antisocial Personality Disorder (ASP) [DSM‐III‐R; 301.70], and the unweighted ASP symptom count also correlated significantly with testosterone levels in these subjects. We suggest that individuals whose life histories involve numerous antisocial behaviors tend to have high testosterone levels even when interpersonal violence is excluded. This, however, does not eliminate the possibility that males who are characterized by high hostility may also have elevated testosterone levels. Violent predisposition and antisocial conduct beginning in early adolescence predict adult aggressive behaviors, which are augmented by power‐related alcohol expectancies and alcohol abuse. Aggr. Behav. 25:113–123, 1999. © 1999 Wiley‐Liss, Inc.     

Attempted suicide, self-harm, and violent victimization among regular illicit drug users

Relationships among attempted suicide, nonsuicidal self-harm, and physical assault were examined in 400 regular users of heroin and/or psychostimulants. Twenty-eight percent had episodes of nonsuicidal self-harm, 32% had attempted suicide, and 95% had been violently assaulted. The number of suicide attempts and nonsuicidal self-harm incidents were correlated (ρ = 0.44). There were also significant correlations between the number of assaults and nonsuicidal self-harm incidents (ρ = 0.17), and suicide attempts (ρ = 0.27). The mean age onset for non-suicidal self-harm (18.9 yrs) was significantly younger than that of initial suicide (22.3 yrs). The age at initial physical assault (16.0yrs) was significantly younger than that of nonsuicidal self-harm and initial suicide attempt. Screening for all forms of violence appears warranted when determining suicide risk for this population.     

Individual differences in prejudice and associative versus rule‐based forms of transitive reasoning

Two experiments examined whether individual differences in prejudice are associated with different reasoning styles when targets and nontargets of prejudice are processed in the same context. High‐prejudice and low‐prejudice participants studied pairwise relations between four persons (one a prejudice target, three nontargets). Stereotypes were made salient by using specific ethnic names and stereotypic traits to define relations between the targets. Relations between the persons were always stereotype congruent in Experiment 1, whereas they were sometimes stereotype incongruent in Experiment 2. We examined study time, relational memory, and transitive reasoning in both experiments. The results of both experiments indicated that the high‐prejudice participants studied sets of relations presented to them faster than did the low‐prejudice participants. The high‐prejudice participants were also more likely to show impaired relational memory and reasoning about nontarget persons but no such limitations with respect to target persons. This novel evidence that prejudice might substantially impair memory and transitive reasoning processes about nontarget persons is discussed in the light of alternative theoretical frameworks in the social cognition and emotion domains. Copyright © 2011 John Wiley & Sons, Ltd.     

What Makes Susie Cry? A Symptom-Context Study of Family Therapy

The aim of this investigation was to examine the context of recurrent crying episodes during family therapy sessions. We tested the relative contribution of social versus individual intrapsychic variables within a 10-session, videotaped, structural family therapy. Segments of therapy before crying episodes when compared with control (non-crying) segments were found to have higher levels of the following variables: involvement with others in the room, rejection, and concern about supplies. Two family variables were also higher before crying episodes: family discussion about patient, and patient receives hostility. A stepwise discriminant function analysis using these variables indicated that family discussion about the patient was most important in signaling onset of crying. The results are discussed in terms of individual and family theories of symptom formation as illuminated through this case study.     

Personality,Parental, and Media Influences on Aggressive Personality and Violent Crime in Young Adults

Debate remains regarding the interaction between predictor variables for aggression, including family environment, media violence, and personality. The current study examined the contributions of gender and personality, exposure to physical abuse and violence in the family, and exposure to media violence in both television and in video games on violent criminal activity. Data from young adults (n = 355) indicated that personality characteristics and direct physical abuse significantly predicted violent crime. Exposure to television and video game violence were not significant predictors of violent crime. These results elucidate the complex interplay between multiple factors related to the etiology of violent crime. These results also call into question the belief that media violence is involved in the etiology of violent crime.     

THE EFFICACY OF WOMEN'S RESISTANCE STRATEGIES IN RAPE SITUATIONS

The effectiveness of women's resistance strategies for reducing the severity of sexual abuse and physical injury during sexual assaults was analyzed in a variety of assault circumstances. Data were obtained from police reports and court testimonies of 274 women (96% White, 4% Black) who either were raped or avoided rape by subsequently incarcerated violent stranger rapists. Statistical analyses showed that particular resistance strategies were effective in specific situations. Women who fought back forcefully were more likely to avoid rape than women who did not fight back, regardles of whether a waepon was present. Forceful fighting resistance was related to increased physical injury when a weapon was present, but most physical injury was caused by nonlethal weapons. Women who screamed or fled when confronted with weapons experienced less severe sexual abuse. Increased physical injury was associated with pleading, crying, or reasoning indoors. Women who used drugs or alcohol experienced more severe sexual abuse and physical injury.     

Gender symmetry in prevalence, severity, and chronicity of physical aggression against dating partners by university students in Mexico and USA

The paper reports results from analyses of the physical aggression against dating partners by four samples of university students in Ciudad Juarez, Mexico, Mexican Americans and Non-Mexican Whites in El Paso and Lubbock Texas, and New Hampshire (N=1,544). The percent reporting partner violence (PV) was high in all samples, but also differed significantly between samples. The lowest rate was in New Hampshire (29.7%), followed by Texas, Non-Mexican Whites (30.9%), Texas Mexican American (34.2%), and the highest rate was in Juarez (46.1%). When only severe assaults were compared, the differences between samples was similar, i.e., lowest in New Hampshire and highest in Juarez. In all four samples, there was no significant difference between males and females in either the overall prevalence of physical aggression or the prevalence of severe attacks. Among the 553 couples where one or both of the partners were violent, in almost three quarters of the cases (71.2%) there was gender symmetry in the sense that both partners engaged in this type of behavior. When only one partner was violent, this was twice as likely to be the female partner (19.0%) as the male partner (9.8%). Among the 205 couples where there was an act of severe aggression, symmetry was less prevalent (56.6%), but when only one partner was violent, it was again twice as likely to be the female partner (29.8% female only versus 13.7 male partner only). These results are consistent with the gender symmetry in PV found in many studies. They extend those results by showing that gender symmetry prevails in four different cultural contexts. The presence of gender symmetry in these different cultural contexts, combined with studies showing that women are injured more often and more seriously by partner-assaults, and studies showing that women initiate PV as often as men, suggests that programs and policies aimed at primary prevention of PV by women are crucial to ending PV and for reducing the victimization of men and women.     

Delinquenzverläufe jugendlicher Sexualmörder

Sexual homicides by juvenile offenders are statistically rare and until now only a few studies explored this phenomenon. Studies on forensic psychiatric court reports and follow-up data from federal criminal records were used to investigate the delinquency of a sample of 19 juvenile sexual homicide perpetrators from their childhood up to the mean age of 45 years of age. More than the half (58%) committed or attempted sexual assaults prior to the sexual homicide. Seven from 13 who were released from custody (54%) committed sexual or violent reoffences. In a long-time analysis as much favourable as unfavourable developments were found. The results suggest that most of the persons who commit sexual homicides as juveniles already committed sexual offences before and have a high risk of sexual and violent reoffending even a long time after the homicide.     

Deindividuation,anonymity, and violence: findings from Northern Ireland

The author examined the relation between anonymity and aggression in violent interpersonal assaults that occurred in Northern Ireland. Of the 500 violent attacks that the author studied, 206 were carried out by offenders who wore disguises to mask their identities. The findings revealed that significant positive relationships existed between the use of disguises and several measures of aggression. Disguised offenders inflicted more serious physical injuries, attacked more people at the scene, engaged in more acts of vandalism, and were more likely to threaten victims after the attacks. The author discussed these results within the framework of deindividuation theory.     

Assaultive behavior resulting from marital conflict

Recent evidence shows that dangerous acts, especially serious ones, are highly likely to be directed against family members. This fact calls for interpersonal assessment of dangerous behavior. The present authors have undertaken preliminary study of fighting behavior (verbal and physical) between married couples. A semistructured interview procedure has been devised to establish the methods used by both partners in carrying on their disputes. The authors propose that there are three broad types of fighting patterns to be found:constant high—sustained level of balanced antagonism;unpredictable volatile—low level of overt antagonism with occasional difficult-to-predict highly violent episodes;steady escalation—increasing levels of violence over time. Data from one couple representing each pattern are presented to demonstrate different parts of the interview schedule.     

Correlates and consequences of exposure to video game violence: hostile personality, empathy, and aggressive behavior

Research has shown that exposure to violent video games causes increases in aggression, but the mechanisms of this effect have remained elusive. Also, potential differences in short-term and long-term exposure are not well understood. An initial correlational study shows that video game violence exposure (VVE) is positively correlated with self-reports of aggressive behavior and that this relation is robust to controlling for multiple aspects of personality. A lab experiment showed that individuals low in VVE behave more aggressively after playing a violent video game than after a nonviolent game but that those high in VVE display relatively high levels of aggression regardless of game content. Mediational analyses show that trait hostility, empathy, and hostile perceptions partially account for the VVE effect on aggression. These findings suggest that repeated exposure to video game violence increases aggressive behavior in part via changes in cognitive and personality factors associated with desensitization.     

Desensitization to media violence: links with habitual media violence exposure, aggressive cognitions, and aggressive behavior

This study examined the links between desensitization to violent media stimuli and habitual media violence exposure as a predictor and aggressive cognitions and behavior as outcome variables. Two weeks after completing measures of habitual media violence exposure, trait aggression, trait arousability, and normative beliefs about aggression, undergraduates (N = 303) saw a violent film clip and a sad or a funny comparison clip. Skin conductance level (SCL) was measured continuously, and ratings of anxious and pleasant arousal were obtained after each clip. Following the clips, participants completed a lexical decision task to measure accessibility of aggressive cognitions and a competitive reaction time task to measure aggressive behavior. Habitual media violence exposure correlated negatively with SCL during violent clips and positively with pleasant arousal, response times for aggressive words, and trait aggression, but it was unrelated to anxious arousal and aggressive responding during the reaction time task. In path analyses controlling for trait aggression, normative beliefs, and trait arousability, habitual media violence exposure predicted faster accessibility of aggressive cognitions, partly mediated by higher pleasant arousal. Unprovoked aggression during the reaction time task was predicted by lower anxious arousal. Neither habitual media violence usage nor anxious or pleasant arousal predicted provoked aggression during the laboratory task, and SCL was unrelated to aggressive cognitions and behavior. No relations were found between habitual media violence viewing and arousal in response to the sad and funny film clips, and arousal in response to the sad and funny clips did not predict aggressive cognitions or aggressive behavior on the laboratory task. This suggests that the observed desensitization effects are specific to violent content.