Pain-induced aggression: An ethological perspective

Pain-induced aggression has been studied mainly in animals, but generalizations are made to human aggression, noteably in Berkowitz’s “aversive-stimulation” view. This review reevaluates the motivational basis of pain-induced attack by considering it from an ethological perspective. Studies supporting the view that shock-induced attack is fear-motivated are briefly reviewed before consideration of evidence that does not support this view, from naturally-ocurring examples of pain-induced attack, and from examples of sex and hormonal effects. A reconcilliation between the apparently conflicting views is suggested by distinguishing between the functional (competitive-protective) dimension and the causal (offensive-defensive) dimension. It is proposed that pain-induced attack is protective in function but can be offensive or defensive (or both) in its form; the offensive form is only rarely observed under laboratory conditions. The implications of this view are discussed (1) for the use of shock-induced fighting as an animal model of aggression; and (2) for studies of human pain-induced aggression. Ethical issues surrounding shock-induced aggression research are considered.     

The offensive nature of maternal aggression in mice: Effects of fluprazine hydrochloride

The phenylpiperazine fluprazine hydrochloride was used to test the hypothesis that maternal aggression in laboratory mice reflects offensive motivation. Lactating females (n = 8 per condition) tested for aggression following drug treatment (1.0 mg/kg and 5.0 mg/kg of fluprasine) were significantly less aggressive than saline controls according to all measures used. The findings support the hypothesis that maternal aggression is offensive in nature, and provide no evidence that maternal attack is a mixture of offensive and defensive tendencies.     

Offensive and defensive aggression in humans: A longitudinal perspective

Offensive and defensive aggression were distinguished on the basis of associated events. Behavior delivering noxious stimuli was defined as defensive when it was a response a threatening situation and as offensive when it was an unprovoked act. The existence of a general aggression factor was implied by the finding that initiators of aggression also readily defend themselves if attacked. The use of a peer nomination and teacher rating variable for offensive aggression, “Attacks without reason, teases others, naughty things”; and another for defensive aggression, “Defends him/herself if teased, but does not tease or attack others without reason,” yielded differential results. Offensive aggression at age 14 was significantly predicted by aggressive behavior age 8, while defensive aggression was not. Intercorrelations of rating variables at 14 showed that offensive aggression was related to weak self-control and defensive aggression to strong self-control. Only offensive aggression at age 14 predicted criminality at age 20. The results indicate a diversity of motivations for aggressive behaviors, as suggested by observations on animal behavior.     

Effects of septal-forebrain lesions on maternal aggression and maternal care

Septal-forebrain lesions significantly increased the defensive reactions of lactating Long-Evans rats (n = 13) relative to nonlesioned control females. The lesions greatly enhanced defensive behaviors on a number of standard tests (e.g., responsiveness to humans and anesthetized conspecifics) while abolishing aggression toward intruding male conspecifics. The lesions also produced a striking disruption in maternal behavior as evidenced by absence of nest building, reduced litter weights, failure to retrieve, lick, or nurse pups, and increased cannibalization. While these results cannot be interpreted as indicating that maternal aggression is equivalent to offense, they are congruent with such a view. Certainly they are not supportive of a view that maternal aggression is primarily defensive. The lesion-induced abolition of maternal attack may have resulted from an inhibition of offensive tendencies by heightened defensiveness and/or reduced pup stimulation. There was no evidence that the lesion-induced impairment in maternal behavior resulted from a failure to sequence the individual behavioral acts comprising maternal behavior. Rather, all features of maternal care seemed to be greatly attenuated.     

Effects of reactivity to dorsal stimulation and social role on aggressive behavior in laboratory rats

Rats were selected on the basis of reactivity to dorsal tactile stimulation and then tested in a resident-intruder paradigm. While reactivity of residents did not influence the occurrence of agonistic behaviors or wounding of residents and intruders, reactivity of intruders did affect offensive and defensive patterns of interactions and the wounds sustained by residents and intruders. Subsequent to resident-intruder testing, rats were tested for shock-induced aggression. The pattern of the results and the results of additional experiments demonstrated that resident-intruder experience could affect subsequent shock-induced aggressive behavior.     

Factors influencing maternal attack on conspecific intruders by lactating female “TO” strain mice

Factors regulating maternal attack in “TO” strain mice were investigated to determine 1) optimal conditions for inducing this behaviour and 2) the likely utility of this activity. Lactating females were more likely to attack male intruders than female intruders. The mate's presence reduced maternal attack in this strain, or (putting it conversely) aggression was generated in the male's absence. Removal of the mothers from their litters for four to five hours also suppressed maternal attack. Investigation of the bite targets in the maternal attack suggested that it is a defensive, rather than an offensive, response.     

Does fear modulate defensive and offensive types of maternal attack in mice?

Swiss CD‐1 lactating mice show a different pattern of attack toward intruders of differing sex, displaying defensive attack against the male (bites on the head and ventrum associated with fear) and offensive attack against the female (bites on the back and flanks with no elicitation of fear). This dichotomy may reflect diverse functions of maternal aggression: the attack toward males (the more infanticidal gender in laboratory strains) has been interpreted as a counterstrategy to infanticide, whereas the attack toward females may serve to establish a social hierarchy or to space rivals of the same sex. In terms of proximal mechanisms, fear may be a key factor involved in the modulation of the different patterns of attack. In Experiment 1 we compared the pattern of attack of lactating females in Swiss CD‐1 and Wild mice toward male and female intruders in relation to fear components of behavior of the attacking dams. Results showed that in Swiss mice, male intruders were attacked with a defensive type of attack accompanied by high levels of fear, whereas female intruders did not elicit fear in the attacking animal but were attacked with an offensive pattern. In Wild mice, both types of intruders were attacked with a defensive pattern; notwithstanding, fear was evident only toward male intruders. This suggests that fear is not totally responsible for the expression of the defensive type of attack. To test the hypothesis that defensive attack toward male and female intruders may be related to the infanticidal potential of the intruder, Experiment 2 examined levels of infanticide in both male and female Swiss CD‐1 and Wild mice. Swiss female mice showed virtually no infanticidal behavior, whereas Swiss males and both sexes of Wild mice showed similarly high levels of infanticide (55%–75%). From a game theory perspective, the defensive pattern of maternal attack toward female intruders in Wild mice is discussed as “extreme” defense of a high value resource and thus, functionally, a competitive form of aggression. Aggr. Behav. 26:193–203, 2000. © 2000 Wiley‐Liss, Inc.     

Effects of fluprazine (DU 27716) upon aggressive and sexual behavior of testosterone-treated female rats

Female rats, chronically treated with Testosterone Propionate (TP), were injected with Fluprazine (DU 27716) or saline and tested for social aggression, masculine and feminine sexual behavior. Fluprazine-treated females were less aggressive than saline-treated females, as indicated by a shift from offensive to less offensive parameters of aggression. At the same time, mounting in Fluprazine-treated females was almost totally abolished, both in aggression tests and in tests for sexual behavior. Feminine sexual responses increased during aggressive encounters but were slightly inhibited when females were confronted with sexually active males. Females treated with Fluprazine and tested for mounting with a receptive female showed a substantial increase of offensive aggression directed at the receptive stimulus female. It is concluded that Fluprazine does not selectively inhibit offensive aggression in TP-treated female rats.     

Fear and aggression in the rat

The effect of fear on two types of aggression in rats was investigated by adding a cat stimulus to a colony in which the dominant male was attacking an intruder (offensive aggression), or, to a tube test situation in which defensive biting was measured before and during tail shock. The cat completely abolished offense in the colony; when the cat was presented and removed before a strange rat was placed in the colony, attack on the intruder was also reduced. In contrast, defensive biting was unchanged or even slightly potentiated by the presence of the cat, demonstrating a separation of the effects of fear on offensive and defensive aggression.     

On the dual nature of maternal aggression in rats

Presentation of a natural predator, a cat, was used to differentiate elements of maternal attack by female rats on a male intruder. Following exposure (without direct physical contact) of post-partum females to a cat or to a toy stuffed cat (control group), the females were replaced in their home cages and presented with a male intruder rat. Cat exposure reliably decreased lateral attack to the intruder, as well as locomotion, but had no effect on either jump attack or an upright defensive posture (boxing). Since predator exposure produces a somewhat durable increase in defense, along with inhibition of nondefensive behavior, these results suggest that maternal aggression represents a mixture of offensive, usually related to competition, and defensive (protective) behaviors. The results indicate that maternal aggression, as a parental care behavior, appears to be at least partially resistant to fear. © 1996 Wiley-Liss, Inc.     

Relationship between mousekilling and conspecific aggression in the male rat

In order to investigate the relationships between mousekilling and conspecific aggression, behavioral variables of killer and nonkiller rats were compared in a “resident-intruder” paradigm, in resident as well as in intruder animals. The occurrence of offensive items (offensive sideways, attack) was significantly higher in killer rats when they were residents; their corresponding opponents displayed more defensive behaviors. No significant difference in aggressive behaviors was noted when the comparison was done in the intruders. These results and those of previous studies suggest that there is a correlation between mousekilling and intraspecific offensive behaviors. Some similarities in the situations where both behaviors are elicited–eg, introduction of an unfamiliar intruder into a familiar environment–may contribute to the existence of such a correlation and the possibility of common mechanisms underlying both behaviors is discussed.     

Relationship between shock-induced aggression and other laboratory tests of agonistic behavior in rats

The utility of the shock-induced aggression paradigm has been questioned in recent years. Studies were reviewed that demonstrated similar effects of independent variables on shock-induced, resident-intruder, and home-cage aggressive behavior. Correlations between naturally occurring aggression and shock-induced aggression, studies showing the influence of naturally occurring agonistic experience on shock-induced aggression, and the effects of shock-induced aggressive experience on resident-intruder behavior were also reviewed. It was argued that continued research into shock-induced aggression and its relationship to other laboratory paradigms would be useful, and that abandonment of the paradigm at this time would be premature.     

Moral Evil and Leibniz’s Form/Matter Defense of Divine Omnipotence

The purpose of this paper is to demonstrate that Leibniz’s form/matter defense of omnipotence is paradoxical, but not irretrievably so. Leibniz maintains that God necessarily must concur only in the possibility for evil’s existence in the world (the form of evil), but there are individual instances of moral evil that are not necessary (the matter of evil) with which God need not concur. For Leibniz, that there is moral evil in the world is contingent on God’s will (a dimension of divine omnipotence), with the result that even though it is necessary that God exerts his will, there are particular products of his will that are contingent and unnecessary—including human moral evil. If there are instances of evil which are contingent on God’s will and yet unnecessary, then the problematic conclusion for Leibniz’s view must be that human evil depends upon divine concurrence, not just for its possibility in the world (which is necessary) but for its instance (which is contingent). If the form/matter defense of omnipotence contains a true paradox, then God concurs in the form as well as the matter of evil. To assuage this difficulty for Leibniz, I will argue that he could either give up an Augustinian notion of evil, or rely upon a distinction between *potenta absoluta* and *potenta ordinate*, which was popular among important thinkers in the medieval period.     

New Directions in Measuring Reactive and Proactive Aggression: Validation of a Teacher Questionnaire

The well-known distinction between reactive and proactive aggression is theoretically important but empirically controversial. Recently, aggression researchers have argued that we should separate the form and function of aggression to make a clearer distinction between reactive and proactive aggression. This article describes the validation of a new teacher-report Instrument for Reactive and Proactive Aggression (IRPA) that assesses the form separate from the function of aggression. We demonstrated good discriminant, convergent, and construct validity of the IRPA in a sample of 427 children aged 10 to 13. Reactive and proactive functions of aggression were independent constructs (r = 0.03) which indicates excellent discriminant validity. Convergent validity was satisfactory; scores from the IRPA were moderately to highly related to scores from the widely used Teacher Rating Instrument, TRI (Dodge and Coie in Journal of Personality and Social Psychology 53:1146–1158, 1987). Additionally, reactive and proactive aggression showed unique correlations with most a priori hypothesized theoretically relevant variables, which indicates construct validity. (150 words)     

Offensive and defensive bite-target topographies in attacks by lactating rats

The attacks by resident lactating Wistar rats on sexually naive conspecifics of both sexes were examined. Male and female intruders were equally attacked in terms of frequency and number of bites, but the topographies of biting seen in these encounters were different. Similarly to male-male agonistic interactions, females were attacked in a fashion which avoided bites to the head and snout (“offensive” attack), whereas males were frequently bitten on such vulnerable regions (“defensive” attack). This dichotomy in bite pattern suggests that different motivations and functions underlay maternal aggression in these situations. The defensive attack on males may be a deterrent to infanticide since only male intruders counterattack lactating females and kill their pups. The attack on females may be concerned with resource competition.     

Manipulations of vasopressin alter aggression differently across testing conditions in monogamous and non‐monogamous Peromyscus mice

Differences in the distribution of arginine vasopressin (AVP) and a subtype of AVP receptors, the V_1a receptor, may explain dissimilarities in social behavior of monogamous and non‐monogamous rodents. Intracerebroventricular infusions of AVP and a V_1a antagonist were used in sexually naive males of two mouse species, the monogamous and highly aggressive California mouse (Peromyscus californicus) and the non‐monogamous and less aggressive white‐footed mouse (P. leucopus), to begin testing the interaction between the social system of a species and the effects of AVP on aggression. Two testing conditions, the resident‐intruder aggression test (R‐I) and the neutral arena aggression test, were used because they may differ in function and underlying biological mechanisms. In the R‐I test, administration of the antagonist lengthened attack latencies in California mice. In contrast, blocking V_1a receptors did not alter attack latencies in the R‐I test in white‐footed mice or in the neutral arena aggression test in both species. AVP also did not alter aggression in either species in either behavioral test. Overall, these results suggest that AVP may be more likely to be associated with offensive aggression as measured in the R‐I test than with neutral arena aggression and that the effects of AVP manipulations may differ between monogamous and non‐monogamous rodents. Aggress. Behav. 31:000–000, 2005. © 2005 Wiley‐Liss, Inc.     

Aggressive behavior inhibition by serotonin and quipazine injected into the amygdala in the rat

The effects on aggressive behavior, open-field activity, and pain threshold of bilateral microinjections of serotonin (20 micrograms) and quipazine (20 micrograms), the direct serotonergic receptor agonist, into the cortico-medial amygdala were investigated in Wistar rats. Both drugs significantly prolonged the attack latency in isolated killer rats (predatory aggression model), and suppressed the incidence of aggressive postures/attacks in shock-induced fighting test (affective aggression). The only difference in the open-field behavior was the lower number of central square entries in drug-treated compared to saline-injected rats. None of the substances produced any significant change in jump threshold. It is concluded that stimulation of serotonin receptors within the amygdala produces inhibition of affective and muricidal behavior in isolated rats. The effect does not seem to be dependent on changes in general activity and pain sensitivity.     

Erikson,psychology, and religion

The writings of the late Erik H. Erikson (1) have contributed directly to the psychological study of religion, (2) were amenable to the efforts of others to develop normative theological arguments, and (3) might be seen as themselves examples of contemporary, nontheological accounts of the religious dimension of human existence. This paper begins by reviewing the principal contributions that Erikson made to the psychological study of religion, followed by a review of the uses that have been made of Erikson's work for normative/constructive activities in such areas as practical theology and pastoral counseling. I will then argue that Erikson's writings — when viewed in the vein of William James's radical empiricism and functionalist accounts of human religiosity — identify an irreducibly religious dimension to normative human functioning. Erikson's functionalism constitutes a form of nontheological religious thinking that speaks directly to concerns presenting themselves in contemporary culture.     

Effects of serotonin receptor agonists and antagonists on offensive aggression in mice

The effects of serotonin receptor agonists 5-methoxytryptamine and quipazine, and antagonist mianserin on resident-intruder offensive aggression were investigated. Both agonists reduced aggression. The fact that 5-methoxytryptamine preferentially binds to 5-HT-1 receptors strongly suggest that the decreased aggression with S-methoxytryptamine was related to stimulation of an inhibitory 5-HT-1 receptor. It is also suggested that the reduction in aggression with quipazine was related to quipazine's preferential binding to the 5-HT-1 receptor. The 5-HT-2 receptor antagonist mianserin reduced aggression suggesting that 5-HT-2 receptor blockade is inhibitory for aggression. Thus, two serotonin classes of receptors may be differentially involved in offensive aggression.