Attack priming and satiation in female golden hamsters: Tests of some alternatives to the aggression arousal interpretation

“Priming” a female hamster by allowing it a single attack on an intruder placed into its home cage transiently decreases the latency and increases the probability of attack on a second trial. Although we have previously argued that this priming effect reflects an increase in aggressive arousal, an alternative interpretation is that the fear elicited by placing a foreign object into the subject's home cage is reduced when it happens again on the second trial. Another interpretation is that priming is an effect of intruder novelty, i.e., the subject perceives a difference between the first and second intruders which causes it to attack the second more quickly. Experiment 1 compared the standard two trial paradigm with different intruders to trials in which (1) the first intruder was withdrawn and used again in the second trial, and (2) the intruder remained in the cage following the first attack. All intruders were pretreated with the analgesic-sedative methotrimeprazine to reduce the variability of their behavior. Neither hypothesis tested in Experiment 1 was supported, strengthening the interpretation of attack priming as a manipulation that affects primarily internal motivational mechanisms specific to aggression. Allowing a hamster to carry out a protracted series of attacks produces a “satiation” effect that is the reverse of priming, i.e., the latency of a subsequent attack is increased and its probability reduced. It is possible that the attack satiation observed in our earlier studies was not the result of processes internal to the subject, but could have been due to habituation to a particular intruder or to certain stimuli emitted by it during the protracted interaction. In Experiment 2 subjects were given three sessions of 10 successive trials using either 1 intruder presented repeatedly, 2 intruders presented alternately, or 10 different intruders presented once each. No difference among conditions was found in this study either suggesting that subject's aggressive behavior is insensitive to whatever changes may occur in intruders' behavior or other stimulus characteristics when they have been treated with methotrimeprazine. The lack of differences among test conditions in both experiments is most likely due to the efficacy of the drug in “standardizing” intruder behavior. Experiment 2 also revealed an interesting difference in two measures of attack latency. The time elapsing between intruder presentation and attack, i.e., the standard measure of latency, decreased from the first to the fourth trail; it then increased steadily over the remaining trials. The cumulative time that the subject remained in contact with the intruder prior to attack, a measure more indicative of attention to the intruder, dropped to an asymptotic value by the second trial. This difference suggests that the satiation effect may be accounted for by subjects' increasing avoidance of the intruders over trails, perhaps as a way of regualting their level of aggressive arousal.     

Infanticide and maternal aggression: Synchrony of male and female reproductive strategies in mice

Thirty-six percent of male mice from three strains attacked newborn pups sired by another male. No male attacked its own offspring. Females did not show differential aggression toward males likely (strangers) or unlikely (sires) to attack their pups. Both forms of aggression were unaffected by housing in rooms which did or did not contain the aggression targets. The three strains differed in strength of maternal aggression but not in the incidence of infanticide. Females showed more aggression when mated with males of the same, rather than a different, strain but no differences with intruders of the same or a different strain. Infanticide by males is best viewed as a postcopulatory, intermale-competition strategy, and maternal aggression as a counter strategy.     

Effect of chronic ethanol administration on intermale aggression in rats

An experiment was performed to study the effect of chronic ethanol administration on intermale aggression in rats using a 24-hour resident-intruder test. During the resident-intruder test residents displayed virtually all of the agonistic behaviors, and intruders displayed virtually all of the defensive behaviors. Intruders treated with ethanol displayed more defensive behavior and elicited more agonistic behavior than control intruders. Twenty minutes into the resident-intruder test intruders showed the greatest increase in corticosterone (338% vs. 129%), while residents showed the greatest increase in testosterone (103% vs. 18%). On the 2nd day of the resident-intruder test intruders lost more weight than residents (21.5 g vs. 10.2 g). Plasma corticosterone levels remained elevated for the intruders, and in particular for those intruders displaying defensive behaviors regardless of the resident's behavior. Plasma testosterone levels remained elevated for those residents that were paired with intruders that displayed defensive behaviors regardless of the resident's behavior. The frequency and severity of biting attacks by ethanol residents was significantly greater than that of control residents. In addition, the locus of biting attack shifted from the upper back of intruders paired with control residents to the flanks, tail, lower feet, and ventral surface on intruders paired with ethanol residents.     

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.     

Ethological analysis of the male rat's socioagonistic behavior in a resident-intruder paradigm

The object of the present study was to assess the rat's socioagonistic behavior by means of ethological procedures. Two groups of male Wistar rats were used: 33 residents and 66 intruders. To allow reliable characterization of social and agonistic patterns, social interactions were increased by the isolation of residents and, on the other hand, both offense in residents and defense in intruders were increased by differences in weight, agonistic experience, and habituation to the enclosure. Encounters were videotaped, and the animals' behavior was analyzed by a 27-pattern ethogram and a software package made up to this end. Several patterns parameters were quantified, and two ethological mathematical models were employed: sequential analysis of preferential directions and cluster analysis based on similarities between patterns. Following mean latencies of the most frequent elements, the first four pattern sequences appeared to be the same in both groups of animals. From the fifth pattern on, residents displayed mainly dominance and threat, whereas intruders showed defensive and submissive patterns. Attack was also displayed by residents, but less frequently than dominance and threat. The alpha status was established by two sorts of domination, either through dominance and threat or by attack. The mean frequency of the intraindividual transition of patterns was higher in residents than in intruders. Pathway graphs, derived from sequential analysis, showed some common dyads, triads, or quadrads of patterns, but they basically defined different behavior structures in residents and intruders. Dendrograms, obtained by cluster analysis, allowed classification of patterns into behavior categories. The categories in residents were exploration, dominance, threat, and attack, and they encompassed 18 elements; in intruders the categories were exploration, dominance, and defense, and they consisted of nine patterns. A submissive category composed of three patterns could be also deduced considering similarity results. To summarize, six behavior categories were obtained: one “socioindividual” (exploration) and five “agonistic” (dominance, threat, attack, submission, and defense). In conclusion, the present study shows how ethological procedures may help to elucidate the rat's socioagonistic behavior and to classify the observed patterns into behavior categories.     

Different patterns of biting attack employed by lactating female mice (Mus domesticus) in encounters with male and female conspecific intruders

Attacks by resident lactating female mice were examined in a variety of situations. Relatively few attack bites to vulnerable body regions were seen when pairs of unfamiliar lactating females fought, establishing social status prior to communal nesting. Sexually naive male and female intruders were equally prone to attack by lactating females, but patterns of bite attack generated by them were very different; males received the more damaging attacks. More signs of "fear" were seen in the lactating females' responses to male rather than female intruders. Varied motivations may underlie attacks by lactating females directed to conspecific intruders. Defensive patterns of biting by lactating females are more consistently directed towards males, intruders that are more likely to harm or destroy the litter. Although attacks by females rarely thwarted infanticide by male intruders, the behavior may acutely protect parental investment.     

MAKING IT EXPLICIT AND CLEAR: FROM “STRONG” TO “HYPER‐” INFERENTIALISM IN BRANDOM AND PEIRCE

Abstract: This article explores how Robert Brandom's original “inferentialist” philosophical framework should be positioned with respect to the classical pragmatist tradition. It is argued that Charles Peirce's original attack (in “Questions Concerning Certain Faculties Claimed for Man” and other early papers) on the use of “intuition” in nineteenth‐century philosophy of mind is in fact a form of inferentialism, and thus an antecedent relatively unexplored by Brandom in his otherwise comprehensive and illuminating “tales of the mighty dead.” However, whereas Brandom stops short at a merely “strong” inferentialism, which admits some non‐inferential mental content (although it is parasitic on the inferential and can only be “inferentially articulated”), Peirce embraces a total, that is, “hyper‐,” inferentialism. Some consequences of this difference are explored, and Peirce's more thoroughgoing position is defended.     

Maternal aggression toward infanticidal males of different social status in wild house mice (Mus musculus domesticus)

Maternal aggression was examined in wild female mice (Mus musculus domesticus) derived from animals trapped in Alberta, Canada. Lactating females were tested for their behavior toward intruder males during the time of postpartum estrus while housed in a two-cage apparatus containing a defensible nest area. Prior to being used as intruders, sexually naive males were screened for their behavior toward a newborn pup (83% exhibited infanticide). Only infanticidal males were then housed in pairs and allowed to establish a dominance hierarchy. Dominance status was further verified by a urine marking test. The dominant and subordinate infanticidal males were then placed into a lactating female's cage and observed for 1 hr. The test was terminated immediately when a male began to attack the pups. Lactating females attacked the males in both groups, but subordinate males received more intense attacks than dominant males. Dominant males elicited significantly more fear/defense behavior than subordinate intruders. All of the dominant males and only one submissive male attacked the pups. Females were thus successful in blocking infanticide only by infanticidal subordinate males. Since females do not persist in attacking males with high fighting ability, one function of maternal aggression could be to assess the fighting, and resource holding, potential of a future mate. © 1994 Wiley-Liss, Inc.     

Maternal aggression as a model for acute social stress in the rat: A behavioral-electrocardiographic study

Maternal aggression of lactating rats was used to induce acute social stress in a resident-intruder paradigm. Behavioral and electrocardiographic responses of male intruders were simultaneously recorded. Cardiac electrical activity was measured by means of a telemetry system which ensured preservation of intruder's behavioral repertoire. Behavioral response to maternal attack was evaluated in terms of percent time spent in passive/submissive (p/s) and active/non-submissive (a/ns) patterns. This allowed us to classify the intruders as submissive, non-submissive, and intermediates. During the test, a significant decrease of average R-R interval (R-R) compared to baseline conditions and the occurrence of arrythmias of different nature were found. Ventricular arrhythmias, including premature ventricular beats and ventricular tachycardias, were present in all the intruders while R-R fluctuations and II degree atrioventricular (A-V) blocks only appeared in submissive and intermediate rats. Most ventricular arrhythmias occurred within the upper range of heart rate and were preceded by periods of low R-R variability. These electrocardiographic events were temporally associated with a/ns behavioral patterns and were related to an increased prevalence of sympathetic activity. On the other hand, R-R fluctuations and II degree A-V blocks preceded by high R-R variability were synchronized with p/s behavior and were ascribed to a predominant inhibitory effect of vagal activation which becomes more pronounced as the level of sympathetic activity increases. © 1995 Wiley-Liss, Inc.     

Rank order in pairs of communally nursing female mice (Mus musculus domesticus) and Maternal Aggression Towards Conspecific Intruders of Differing Sex

This study examined social behavior between pairs of unfamiliar lactating females, with litters of the same age, at different periods after parturition (3, 7, and 17 days). Tests were generally followed by the formation of communal rearing nests, and subsequent maternal attack on intruders of differing sex was assessed. In all three intervals lactating females showed ritualized attack with formation of clear dominance-subordination relationships before combining litters into communal nests. The dominant females in 90% of cases started to retrieve alien pups into their nests. Agonistic behavior and communal nest formation were most rapid when pups were around 3 days old. Maternal attack on conspecific intruders was mainly displayed by the dominant lactating females. Male and female intruders were equally attacked (in terms of frequency and intensity of attack), but there was less such aggression when pups were around 17 days of age. Nevertheless the topography of biting attack employed against female and male conspecific intruders was different. Females were attacked using a strategy avoiding bites to the head and ventral surface (indicative of “offensive” behavior) whereas males were severely bitten on vulnerable body regions (indicative of “defensive” behavior).     

Neuropharmacological aspects of adaptive pain inhibition in murine “victims” of aggression

This review outlines recent research on a subset of physiological responses in murine “victims” or aggression. In a typical resident-intruder paradigm, the detailed study of intruders has revealed that exposure to conspecific attack (and related stimuli) is associated with two forms of analgesia which appear to be integral components of the murine defensive repertoire. In response to intense/enduring attack, intruder mice display a profound, long-lasting and opioid-mediated analgesia. This reaction is highly correlated with defensive immobility and may function to reduce involuntary cues to further attack. In contrast, the inhibition of pain reactivity in mice tested immediately upon the display of defeat is less intense, shorter-lasting, non-opioid in nature and may function to facilitate active defenses such as escape. As this form of pain inhibition is also evident in intruders exposed to the scent of an aggressive male conspecific, a possible anticipatory defensive function linked to mechanisms of anxiety has been proposed. This hypothesis is supported by 1) the prevention of defeat analgesia by a range of antianxiety drugs (benzodiazepines, 5-hydroxytryptamine_1A [5-HT_1A] receptor agonists, and 5-HT₃ receptor antagonists) and 2) the effects of social defeat on behavior in the elevated plusmaze model of anxiety. These findings are discussed in relation to coping mechanisms in murine “victims” of aggression. © 1995 Wiley-Liss, Inc.     

Women,Nationalism and War: “Make Love Not War”

I analyze the relationship between women and nationalism and argue that women's identity and relationship to the “Other” is different from that of men, hence even when women participate in nationalism it is in a less violent form. I argue, further, that the structures of nationalism are fundamentally homosocial, and antagonism toward women of one's own nation is one of the first forms of attack on the “Other,” and is constitutive of “extreme nationalism.”     

Maternal aggression in mice: Protection of young is a by-product of attacks at the home site

Lactating female mice attacked male intruders in their home cages but showed little attack behavior either in novel cages or in cages with which they had been familiarized. Presence or absence of young did not determine the occurrence of maternal aggression, whereas attacks on the young by the intruder decreased maternal aggression and increased cannibalism of pups by the dams. Apparently, if the function of maternal aggression in mice is protection of the young, such protection occurs because the pups are in a place where attacks are likely to occur and not because the dam “defends” the young.     

On the utility of looking in the “wrong” direction1

In his reply to Lamiell, Foss, and Cavenee (1980), Shweder (1980) fails to address an important question: Did the behavior report task used by Lamiell et al. meet his requirements for a “diffieult memory condition,” or did it not? In light of the nature of the illusory correlation hypothesis and Lamiell et al.'s findings, it is explained that for any of three possible answers to this question (yes, no, or maybe) the integrity of the illusory correlation hypothesis in its present form is compromised. It is also explained that further research on the hypothesis is likely to be pointless, because Lamiell et al.'s findings suggest that it is not salvageable in any form. Finally, it is explained that the incompatibility between lay persons' usage of personality concepts and the study of individual differences does not lead inextricably to the conclusion that the former have no legitimate role to play in a science of personality.     

Ultrasounds produced by rats accompany decreases in intraspecific fighting

Male intruder rats were placed individually into the cage of an established resident on 2 occasions separated by a 7–8 day interval. Residents readily attacked intruders and both animals lost weight during the first encounter. In contrast, no serious fighting occurred on the second encounter, and both intruders and residents maintained their body weight during the 24-hr test. Observation of the intruder's behavior during the first 30 min of each encounter indicated that defensive-submissive postures represent a response to an attack that only temporarily inhibits aggression whereas the emission of 22 kHz calls by the intruder is associated with a relatively permanent decrease in the resident animal's aggressive response.     

Understanding the “ghosts in the nursery” of pregnant women experiencing domestic violence: Prenatal maternal representations and histories of childhood maltreatment

Selma Fraiberg and colleagues (1975) conceptualized the “ghosts in the nursery” as experiences from a mother's past that influenced her ability to form a warm and attuned relationship with her child. Contemporary infant mental health interventions often ask the mother to reflect on her own history of attachment relationships to gain insight into as well as to strengthen her developing relationship with her child. This study investigated the association between a mother's history of childhood maltreatment (CM) and her subsequent prenatal maternal representation during the third trimester of pregnancy. Controlling for domestic violence (DV), distorted prenatal representations were associated with higher rates of self‐reported childhood physical neglect. In addition, DV moderated the relationship between representations and CM, such that women who were exposed to DV during pregnancy and had distorted prenatal representations were least likely to report childhood physical and sexual abuse. Implications are discussed in relation to infant mental health interventions which rely on a parent's ability to psychologically access and reflect on childhood histories to more sensitively parent her own child.     

Effects of mothers’ conversation style and receipt of misinformation on children's event reports

Can memory sharing conversations with mothers lead to errors in children's event memory when mothers are exposed to misinformation about what their children experienced and does this effect vary as a function of maternal memory-sharing style? Mothers were exposed to a false suggestion about a non-shared event and then discussed that event with their children. When later interviewed, those children whose mothers were provided this misinformation were likely to wrongly report experiencing activities consistent with the maternal suggestion and embellish their reports of these activities with elaborative detail. Moreover, children whose mothers spoke in a highly elaborative manner were more likely to recall occurrences in line with the maternal suggestion and provided more fictitious narrative detail describing non-occurring-but-suggested information than did children whose mothers used a less elaborative style. These findings suggest that when mothers hold false beliefs about a non-shared event, an elaborative maternal style is associated with an increase in children's false reports reflecting maternal beliefs.     

Maternal aggression in rats: Changes over pregnancy and lactation in a sprague-dawley strain

Maternal aggression in a Sprague-Dawley strain of laboratory rat (Charles River CD) was explored from Day 1 after mating on Day 0 through Day 24 of lactation (L0-L24). Aggression toward unfamiliar male “intruders” during 10-min tests was low among nonpregnant, nonlactating females and during the first 10 days of gestation. Frequency of attack on intruders increased moderately but significantly by Gestation Day 16 (G16; Experiment 1) or G21 (Experiment 2), a prepartum phenomenon not previously reported in laboratory rats. Levels of aggression were highest, however, during the first 9 days of lactation, when attacks averaged more than 6 per 10-min session. Attacks declined sharply in frequency after L14 and by L24 did not exceed levels observed among nonpregnant females. Experiment 3 examined the importance of the test site (home cage with nest and pups, if any, vs unfamiliar cage without nest or pups) to agonistic behavior associated with pregnancy and lactation. Late pregnant females tested in a novel cage were not aggressive; however, females tested shortly after delivering their pups were highly aggressive, averaging over four attacks per 5-min session. In novel cage tests frequency of attack remained high through L4 but declined significantly by L7. These data are consistent with the hypothesis that maternal aggression at its onset is primarily under hormonal control, but becomes increasingly dependent upon external factors, presumably pup stimulation, during the postpartum period.     

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.     

Divergent Perceptions of Jail Inmates and Correctional Officers: The “Blame the Other-Expect to Be Blamed” Effect1

Inmates and correctional officers in a Lwnty jail made attributions of responsibility and predicted each other's attributions in response to four hypothetical stimulus incidents varying in severity of the inmate's intentional misbehavior and the severity of the officer's intentional retribution. When the misbehavior and retribution were moderate, subjects blamed both participants about equally. However, both over- and underreactions to the stimulus inmate's misbehavior elicited defensiveness, with both officers and inmates more likely to attribute responsibility to their opposite role character. In addition, both inmates and officers appeared to respond defensively to severe but equitable retributions. Subjects blamed each other, and, anticipating the other's defensiveness, expected to be blamed. Examination of the data suggested that subjects may have responded stereotypically rather than empathetically, and that defensiveness impeded rather than facilitated predictive accuracy. Results were consistent with previous research, increasing the generality of the “blame the other-expect to be blamed” effect. Additional analyses indicated that inmates were more likely than officers to notice mitigating circumstances when considering the inmates' responsibility. Three recommendations were made which may help to forestall inmate reactivity to retributions: (1) Jail personnel should have objective and clear definitions as to what constitutes major and minor infractions; (2) inmates should be aware of these criteria; and (3) jail personnel should be sensitive to mitigating circumstances and moderate their retribution or anticipate possible reactivity from inmates.