Psychiatric nurses' attitudes towards inpatient aggression: preliminary report of the development of attitude towards aggression scale (ATAS)

Professional skills to adequately manage patient aggression are a prerequisite for nurses working in psychiatric hospitals. These ‘technical’ skills, however, are necessary but not sufficient for effective nurse intervention. The attitude of nurses' towards client aggression also contributes to their response to a patient's behaviour. In order to study the domains (types) of attitudes towards aggression, a sample was taken of nurses working in the fields of general psychiatry (n=288), psychiatry for children and adolescents (n=242) and psychogeriatrics (n=88). A cross‐sectional survey design was adopted for the study. The Attitudes Towards Aggression Scale (ATAS) consisting of 32 items is presented, representing three types of attitudes towards aggression: aggression as a ‘harming’ reaction, a ‘normal’ reaction and a ‘functional’ reaction. The strongest predictors of the type of attitude respondents had towards the aggressive behaviour of their clients were (1) field, (2) setting they worked in, (3) gender and (4) type of shifts they predominantly had. Although the measure of domains of nurses' attitudes towards aggression needs further psychometric testing, it can be a useful tool in clinical practice for the assessment of staff attitudes towards aggression. This can support the decision‐making about the management of aggressive behaviour on a ward. Aggr. Behav. 00:1–10, 2005. © 2005 Wiley‐Liss, Inc.     

The impact of non‐aggressive behaviour early in aggressive interactions: Sex differences in direct and indirect aggression in response to provocation

Using an adapted form of the Taylor competitive reaction time task (TCRT: Taylor, 1967), we examined the effect of initially non‐aggressive behaviour during aggressive encounters. Specifically, if a person is initially non‐aggressive, but becomes more aggressive later, does an opponent respond more or less aggressively in response? Participants (N = 148) played a competitive reaction time task against a bogus partner, who was either initially non‐aggressive, or initially moderately aggressive, and then delivered increasingly loud noise blasts to participants on trials when the participant lost. Both direct (noise blasts delivered to the partner) and indirect aggression (damage to partner's reputation) were assessed. The impact of whether or not participants expected to meet the partner on direct and indirect aggression was also examined. All participants reduced their direct aggression towards an initially non‐aggressive partner and a partner they expected to meet. However, for females, the switch from initial non‐aggression to later aggression generated a negative evaluation of the partner, exhibited by indirect but not direct aggression.     

Physical aggression: Effects of ethnicity of target and directionality of aggression

Physical aggression of members of a powerful majority ethnic group against an opponent either from a powerless and discriminated against minority or from their own group was tested as a function of aggression directionality and aggressor's attitudes. It was hypothesized that under bidirectional aggression where the opponent could aggress as well, members of the powerful majority group would adjust their aggressive responses to that of their opponent's regardless of his ethnic origin and regardless of aggressor's attitudes. However. under unidirectional aggression where the opponent was powerless, it was expected that those subjects who held unfavourable attitudes toward members of the minority group would be more aggressive against an opponent of that group than against an opponent of his own ethnic group. Subjects who had neutral attitudes would be equally aggressive toward all opponents. Ninety-six 11th grade vocational high school male students of Western origin, were given the opportunity to administer electric shocks to an opponent who was either of Western or Oriental origin in a competitive situation, Subjects were selected according to their attitudes toward Oriental Jews. Half expressed negative attitudes, the other half neutral attitudes. Half of the subjects expected their opponent to reciprocate shocks, the others did not. Contrary to expectations it was found that the attitudes of subjects of Western origin towards Orientals did not effect their aggressive behaviour. When aggression could not be reciprocated, all subjects were more aggressive toward an opponent of Oriental than of Western origin. The findings showed that when aggression was bidirectional, all subjects adjusted their aggressive behaviour, to their opponents'. However, they were less aggressive towards an opponent of Oriental than of Western origin.     

THE EFFECT OF PRIOR AGGRESSIVE OR SEXUAL AROUSAL ON SUBSEQUENT AGGRESSIVE OR SEXUAL REACTIONS IN MALE MICE

Previous aggressive behaviour towards a male mouse was found to decrease sexual behaviour of inexperienced male mice towards a female in heat, mainly due to aggressive behaviour occurring in the sexual situation. Sexual behaviour decreased the aggression displayed in a subsequent encounter with a male. Instead, homosexual behaviour occurred in the situation with the male. After either sexual or aggressive behaviour had been practised, it was no longer influenced by practice of the other activity. Inhibition of aggressive behaviour by successive defeats did not affect sexual performance.     

Moral approval of aggressive acts: A preliminary investigation

A questionnaire was used to investigate 1) the approval of various kinds of aggressive behaviour under different specified circumstances and 2) the arousal of feelings of aggression in imagined situations. In addition, an attitude test was presented which discriminated between the two highest of Kohlberg's levels of moral reasoning [1969]. The subjects were a very varied group of 83 adults (aged 17–68 years) from municipal evening courses in Finland. Aggression was most approved when it was given altruistic purpose. Self-defense was rated as the second highest justification for aggression. Aggression was found least legitimate when the reasons were emotional (drunk, rage). The justification of some types of aggressive behaviour were dependent on the conditions under which they occurred, whereas others appeared independent. Killing and torture were the most disapproved kinds of aggressive behaviour. Another's attack was the most powerful instigator of feelings of aggression, whereas frustration seemed relatively unimportant. Females approved of emotional expressions of aggression to a greater extent than did males. The moral test did not correlate with approval of aggression in general, but a couple of more specific predictions about the effects of level of moral reasoning on attitudes to socially sanctioned forms of aggression were tentatively confirmed.     

Teacher and Parent Perceptions of Relational and Physical Aggression During Early Childhood

Although links have been found between parents’ and teachers’ (caregivers’) attitudes about aggressive behavior, their responses to aggressive behaviour in children, and those children’s own use of aggressive behaviour, most research has focused on primary and secondary school contexts and has examined the influence of parents and teachers separately. The current study explored both parents’ and teachers’ beliefs and intervention strategies for relational and physical aggression in early childhood settings. Teachers (N?=?18; Mage?=?34.8 years) and parents (N?=?68; Mage?=?32.2 years) were presented with vignettes portraying relational and physical aggression. Following each vignette, their perceptions of the seriousness of the act, empathy for the victim, likelihood to intervene, and intervention strategies used to respond to each vignette were assessed. Teachers were also interviewed about examples of aggression that have been seen in preschool age children. Results indicated that caregivers viewed relational compared to physical aggression as more normative, and had less empathy for, and were less likely to intervene in instances of relationally aggressive behaviour. They also recommended more passive intervention strategies towards relationally aggressive children and more direct strategies towards physically aggressive children. Interview responses indicated that teachers perceived the primary cause of aggression to be related to developmental characteristics of the child. Implications for how these findings about adult–child interactions impact the development of relational and physical aggression are discussed.     

What's the point? Towards a methodology for assessing the function of psychiatric inpatient aggression

There are few examples in the literature of the application of functional analysis to psychiatric inpatient aggression. Structural assessment approaches have dominated. This paper introduces a system for classifying the functions of aggression in psychiatric inpatients that was applied to 502 aggressive behaviours exhibited by patients in a secure forensic psychiatric hospital. At least one function was identified for the majority of aggressive incidents; the most common functions pertaining to patients' responses to the restrictions and demands of the inpatient setting, to express anger or to punish others perceived as provocative, and to maintain status. There was little evidence suggesting that aggression was used to obtain tangible rewards, to reduce social isolation, or to simply observe the suffering of others. Differences in the function of aggressive behaviour were found across victim types. Results of this study have implications for the prediction and prevention of inpatient aggression and for the treatment of aggressive inpatients.     

Cooperative social coordination and aggression: Sex and strain differences in the effects of housing on gonadectomized rats with hormone replacement

Laboratory rats were used to investigate sex and strain differences in the effects of aggression on a cooperative behavior in which pairs learn to coordinate shuttling in a rectangular chamber. The level of aggression was manipulated by comparing males and females of the aggressive S3 strain and a less aggressive Sprague-Dawley-derived strain and by housing same-sex partners either together or individually (eight groups, n = 7 pairs per group). Hormone levels were stabilized by gonadectomy and daily injections of the appropriate sex hormone. The only serious coordination deficits were in individually housed males, associated with violent fighting and an extreme dominance/subordinance relationship that was not observed in females. All other groups readily learned and performed the coordination, with evidence that low and moderate levels of aggression could facilitate coordination by evoking species-typical behaviors that increased proximity, synchrony, and differentiation within pairs. The discussion focused on models of affiliative behavior in the study of aggression and the compatibility between moderate levels of aggression and cooperation.     

Cooperative social coordination and aggression: Sex and strain differences in the effects of housing on gonadectomized rats with hormone replacement

Laboratory rats were used to investigate sex and strain differences in the effects of aggression on a cooperative behavior in which pairs learned to coordinate shuttling in a rectangular chamber. The level of aggression was manipulated by comparing males and females of the aggressive S3 strain and a less aggressive Sprague-Dawley-derived strain and housing same-sex partners either together or individually (8 groups, n = 7 pairs per group). Hormone levels were stabilized by gonadectomy and daily injections of the appropriate sex hormone. The only serious coordination deficits were in individually housed males, associated with violent fighting and an extreme dominance/subordinance relationship that was not observed in females. All other groups readily learned and performed the coordination with evidence that low and moderate levels of aggression could facilitate coordination by evoking species-typical behaviors that increased proximity, synchrony, and differentiation within pairs. The discussion focused on models of affiliative behavior in the study of aggression and the compatibility between moderate levels of aggression and cooperation.     

Maternal aggression in mice and rats towards male and female conspecifics

Although postpartum aggression is primarily studied in laboratory mice and rats, it is unclear how the two species compare in terms of the factors associated with peak levels of aggressive behavior. Using the same experimental protocol, we assessed the relative effect of intruder sex and time since parturition on the frequency of maternal aggression in Long-Evans rats and CFW mice. Females were studied for 2 consecutive cycles of pregnancy and lactation. During the first lactation, aggression was tested 2 times per week for 3 weeks in order to select animals that attacked at least once. During the second lactation, both pup care and aggressive behavior were assessed in detail. Testing occurred twice in each lactation week, with postpartum days 1–7, 8–14, and 15–21 considered weeks 1, 2, and 3, respectively. Maternal behavior towards 3 pups was observed for 5 minutes, followed by a confrontation with an intruder. Lactating females encountered female intruders once per week, and male intruders in the alternate weekly test. The same behaviors were measured in the 2 species, except for the tail rattle exhibited by mice and the aggressive posture shown by rats. Lactating rats and mice show similar decreases in pup care behavior as lactation progresses in time; yet the factors associated with peak levels of aggression differ between species. In Long-Evans rats, female intruders receive more attacks, threats, and aggressive postures than males. Frequency of attack bite and sideways threat declines in each passing week of lactation. Lactating mice are more aggressive toward male intruders throughout the lactation period. Mice still attack and threaten during the third week of lactation, but less often in comparison to the first week. Therefore, peak levels of aggression vary in mice and rats both as a function of intruder sex and lactation week.     

Neural correlates of intertemporal choice in aggressive behavior

People often have to make decisions between immediate rewards and more long-term goals. Such intertemporal judgments are often investigated in the context of monetary choice or drug use, yet not in regard to aggressive behavior. We combined a novel intertemporal aggression paradigm with functional neuroimaging to examine the role of temporal delay in aggressive behavior and the neural correlates thereof. Sixty-one participants (aged 18–22 years; 37 females) exhibited substantial variability in the extent to which they selected immediate acts of lesser aggression versus delayed acts of greater aggression against a same-sex opponent. Choosing delayed-yet-more-severe aggression was increased by provocation and associated with greater self-control. Preferences for delayed aggression were associated with greater activity in the ventromedial prefrontal cortex (VMPFC) during such choices, and reduced functional connectivity between the VMPFC and brain regions implicated in motor impulsivity. Preferences for immediate aggression were associated with reduced functional connectivity between the VMPFC and the frontoparietal control network. Dispositionally aggressive participants exhibited reduced VMPFC activity, which partially explained and suppressed their preferences for delayed aggression. Blunted VMPFC activity may thus be a neural mechanism that promotes reactive aggression towards provocateurs among dispositionally aggressive individuals. These findings demonstrate the utility of an intertemporal framework for investigating aggression and provide further evidence for the similar underlying neurobiology between aggression and other rewarding behaviors.     

Stimulus factors in the isolation-induced aggression of Bobwhite quail and Khaki Campbell ducklings

Two studies examined the relative abilities of conspecific-derived visual and tactile stimulation to modulate the occurrence of isolation-induced aggression in Bobwhite quail and Khaki Campbell ducklings. In Experiment 1, subjects were permitted visual stimulation from conspecifics but were deprived of conspecific tactile stimulation. In both species, these subjects subsequently showed significantly less aggression towards conspecifics than birds that had been deprived of both visual and tactile stimulation from conspecifics. In Experiment 2, one group of subjects was permitted conspecific tactile stimulation but was deprived of conspecific visual stimulation. Again for both species, these subjects subsequently exhibited significantly less aggressive behavior towards conspecifics than did subjects that had been both visually and tactually de-prived. In sum, the present research suggests that both tactile and visual stimulation from a conspecific are individually sufficient to reduce isolation-induced aggression in these precocial buds.     

The aggression test as a taxonomic tool: Evaluation in sympatric and allopatric populations of wood-ant species

Ant-workers of Formica lugubris and F. rufa from colonies living sympatrically (from the same area) and allopatrically (from different areas) were tested in pairs using a laboratory aggression test. The aim was to verify whether sharing the same area of origin influences the relationships among heteroeolonials between and within these species which belong to the F. rufa group. The results suggest that a similar degree of agonistic behaviour (ritualised aggression) was shown in sympatric and allopatric conspecific dyads of both species studied. The interactions between F. lugubris and F. rufa were characterised by a low level of overt aggression both in sympatric and allopatric pairs, confirming the interspecific tolerance observed in our previous studies on these wood-ant species. This reduced aggressiveness between workers of F. lugubris and F. rufa coming from the same or a different area can be interpreted on the basis of their sharing common signals, such as odours and patterns of behaviour. Therefore, their mutual tolerance and acceptance can be indicative of a phylogenetic closeness between such species. We propose that an aggression test can be a valid tool for elucidating systematic problems in this taxonomically difficult group of ants. © 1993 Wiley-Liss, Inc.     

Sex differences in aggressive behaviour in various strains of mice

Two nonalbino inbred (C57 BL/6 and C3H/He) and one albino strain (Swiss) of mice were compared for female aggression toward intruders: 1 in period of lactation, 2 in nonlactating state and (3) in nonlactating state but previously rubbed with urine of lactating females; and for male aggression toward familiar or unfamiliar opponents. The results showed that resident females of the C57 and Swiss strain vigorously attack lactating intruders introduced into their cages. This effect was mediated by urinary cues emitted by the latter mice. It was also shown that Swiss residents displayed aggression towards nonlactating females, irrespective of their strain. Groups of C57 residents reacted most aggressively towards Swiss females, less aggressively towards C3H intruders, but did not show any aggression towards their own nonlactating conspecifics. In contrast, none of the C3H resident female groups displayed aggression towards intruding females of any category or strain. The results also showed that the males of the three strains displayed little (Swiss and C3H) or no aggression (C57) towards familiar opponents, whereas they directed increased aggressive responses towards unfamiliar ones. Comparisons among the three strains of mice revealed that Swiss males were the most aggressive in either situation. On the other hand, the finding that C3H males showed aggressive responses suggested that male and female aggression are, in this strain, under separate genetic or hormonal control.     

It is More than Thought that Counts: the Role of Readiness for Aggression in the Relationship Between Ostracism and Displaced Aggression

Research has shown that ostracism results in aggressive behavior towards the ostracising other, but also causes displaced aggression—aggression directed towards an innocent person. Our study investigated whether displaced aggressive responses to ostracism were increased by three types of aggression proneness (readiness for aggression) based on different mechanisms: emotional-impulsive, habitual-cognitive or personality-immanent. Participants (n = 118) played a Cyberball game in which they were either excluded or included, next prepared a hot sauce sample for another person as an indicator of aggression and completed the Readiness for Interpersonal Aggression Inventory. Results showed that ostracism evoked more aggression in participants with high rather than with low emotional-impulsive readiness for aggression. Only this type of readiness moderated the ostracism-aggression relationship indicating that mostly affective mechanisms induce displaced aggressive responses to exclusion.     

Male-female differences and the influence of neonatal and adult testosterone on intraspecies aggression in rats.

Male and female albino rats were tested for intraspecies aggression without the use of shock. In the first experiment, male pairs showed more biting attacks, offensive sideways movements, and self-grooming than did female pairs; male pairs also showed more stereotyped defensive/submissive behaviors and were wounded more frequently. The second experiment examined the effects of neonatal castration and testosterone propionate (TP) administration on fighting. Males castrated at birth attacked other males less frequently than did controls when tested with TP treatment as adults. The TP given at birth to neonatally castrated males restored attacks to control levels. Females given TP as neonates did not differ from either male or female controls. Other aggressive/defensive behaviors, however, did not show this pattern. The results suggest that while the presence of testosterone during a brief postnatal period and during adulthood is necessary for attack behavior to occur, other related behaviors may not be affected in a similar manner.     

Syrian hamster males below an age threshold do not elicit aggression from unfamiliar adult males

In many species, young males are the dispersers, leaving their natal area after weaning to establish a breeding area of their own. As young males disperse, however, they are bound to encounter unfamiliar adult males with established territories. Such interactions between an adult male and a young male may always be agonistic. Alternatively, there may be an age threshold below which aggression is not elicited and above which the adult male is aggressive toward the juvenile male. To test these two alternative hypotheses, we paired 47 young Syrian hamster (Mesocricetus auratus) males ranging from 24 to 65 days of age with 47 adult male hamsters and measured aggressive and investigatory behavior for 5 min. We observed no aggression by the adult toward young males between 24 and 47 days of age or toward the single male that was 49 days of age. Young males that were 50 days of age or older, however, elicited significant levels of aggression from the adults. These results indicate that in Syrian hamsters, young males are less vulnerable to adult aggression up to an age threshold and are more vulnerable to adult aggression beyond that threshold. This pattern may facilitate the establishment of territories by dispersing young males below that age threshold. Aggr. Behav. 37:91–97, 2011. © 2010 Wiley‐Liss, Inc.     

Androgens and aggressive behavior in primates: A review

This review deals with possible central and peripheral effects of androgens upon primate aggressive behavior. One problem that clouds interpretation of experimental work is that measurements of dominance have often been employed, such as competition tests for food and water. Such measures often do not correlate with those obtained by quantifying aggressive interactions. It should be remembered that very few of the 188 primate species have been studied experimentally and that great behavioral and physiological diversity occurs within the order. Therefore, generalizations about the effects of androgens upon aggressive behavior in primates (including man) should be made with caution. Testosterone has an organizing influence upon the foetal brain of rhesus monkeys and may affect the development of neural mechanisms which govern aggression in males. More data are required on primates, however, since rhesus monkeys show some important differences from rodents as regards the effects of androgen upon sexual differentiation of the hypothalamus. In future, marmosets may provide a suitable model for such studies, because there is evidence that sexual differentiation of brain by androgen occurs postnatally in these monkeys. At puberty, male primates show a variety of behavioral changes and, during adulthood, males of seasonally breeding species may be more aggressive during the mating season, when testosterone levels are maximal. This does not indicate a causative relationship between testosterone and aggressive responses, because castration and androgen treatments have little effect upon aggression in prepubertal or adult males of several primate species. Androgens have pronounced effects on sexual responses in adult male monkeys, but their central effects upon aggression are much less important than among rodents. Elec trical stimulation of hypothalamic pathways has been employed to evoke aggressive behavior in marmosets and rhesus monkeys. In the rhesus, preliminary evidence indicates that such pathways show some sensitivity to androgens. In rodents it is known that these areas are richly supplied with monoaminergic neurons, which play an important role in aggressive behavior. There is little evidence on primates, however, and this remains a crucial topic for future research. Peripheral effects of androgens should also be considered. Many prosimians and New World monkeys use scent-marking behaviors and, in males, androgen-dependent chemical cues may be involved in sexual recognition and territorial behavior. This possibility awaits investigation. Finally, plasma testosterone levels may alter as a function of aggression itself; thus levels decrease if male rhesus monkeys are defeated by conspecifics. This might occur because neural events associated with giving (or receiving) aggression also influence pituitary function and hence alter gonadal testosterone secretion. Theoretically, it is possible that such changes in circulating testosterone might affect aggressive behavior via a feedback action on the brain, but the experimental evidence does not support such a view.     

A comparison of human aggression committed by groups and individuals: An interindividual-intergroup discontinuity

Experimental research comparing aggressive behavior committed by groups and individuals is important but sparse. This experiment compared aggressive behavior (i.e., amount of hot sauce allocated for others to consume) in four types of interactions: intergroup, interindividual, group-to-individual, and individual-to-group. The results revealed that intergroup interactions were significantly more aggressive than interindividual interactions. In addition, groups allocated and received significantly more hot sauce than individuals. These effects were not explained by diffusion of responsibility or trait aggressiveness. The experiment reveals two noteworthy conclusions: (1) the interindividual-intergroup discontinuity effect extends to aggressive behavior and (2) interactions in which a group is either the source or target of aggression are situational influences that can increase it.     

Reactive and proactive aggression as meaningful distinctions at the variable and person level in primary school‐aged children

Reactive and proactive aggression is a dichotomous classification of aggression in adults and children. This distinction has been supported by a number of variable‐based and factor analytic studies. Due to high inter‐correlations, however, the reactive—proactive aggression distinction may not be entirely useful for understanding how group or individual aggressive behavior varies in children and adolescents. Drawing on a sample of primary school‐aged children (N = 242) aged 7–12 years, this study sought to determine whether reactive and proactive aggression could be distinguished at the variable‐level and the person‐level in children. Exploratory Factor Analysis of data from an aggression instrument measuring both functions and forms of aggression, found a two‐factor construct of aggression constituted by a reactive and proactive aggression factor. A person‐based analysis was then conducted after classifying children according to the presence of reactive and/or proactive aggression. Discriminant function analysis was used to discern whether classifications on the basis of aggression function produced meaningful distinctions in terms of antisocial traits and emotional valence and intensity measures. Two functions were identified which distinguished children with different combinations of reactive and proactive aggression. Reactive‐only aggressive children were defined primarily by high levels of impulsivity, while proactive‐only children were defined primarily by higher levels of antisocial traits. Children high in both types of aggression exhibited both the presence of antisocial traits and impulsivity. Contrary to recent findings, this suggests that differences in aggression functions remain meaningful at the person level in children. Implications for interventions are discussed.