Effects of age at differential housing and the duration of individual housing/grouping on lntermale fighting behavior and adrenocortical activity in TO strain mice

A study of the effects of the duration of individual and group housing on intermale fighting and adrenocortical activity was conducted in TO strain mice. It was found that fighting and threat increased with progressive isolation up to an asymptote at 56–58 days. ‘Basal’ adrenocortical function differed little under the 2 housing conditions, but after ‘stress,’ mice isolated for short periods, which had not fought when tested for aggression, had lower titers than group-housed counterparts. However, mice that had been isolated for longer periods, and had fought in aggression tests, had higher corticosterone titers than comparable group-housed animals. The effects of a short duration (28–30 days) of differential housing, commencing at different ages, were also studied. The shorter duration adrenocortical changes were largely confirmed. In general, the earlier the age at which the differential housing was imposed, the greater the behavioral differences between animals under each housing condition. It is suggested that this is largely a consequence of a loss of behavioral plasticity in older mice. The data provides little support for the concept of the “isolation stress syndrome,” or for the view that the characteristic fighting exhibited by individually housed mice is a consequence of “social deprivation”.     

The introduction of a group of alien mice (Mus musculus L.) into hierarchically organized groups of five male mice

Groups of 3 male or female Mus musculus were introduced into hierarchically organized colonies of 5 male mice for a period of 8 days. The colonies were of 2 kinds; high-level aggressive (HLA), which had been set up 3 days prior to the introduction of the aliens, and low-level aggressive (LLA), which had been established for 21 days before strangers were introduced. Both males and anestrous females were attacked, but males were attacked 5 times more frequently than females. In HLA colonies most of the attacks on the aliens were by the dominant; in LLA colonies there was no difference in the behavior of dominant and subordinate mice toward strangers. Both aggression toward aliens and intracolony aggression declined over the 8 day experimental period. In HLA colonies the dominant mouse mounted females 5 times more frequently than did either his subordinates or male mice in the LLA colonies. In HLA colonies aliens huddled with subordinates to form a single colony with 1 dominant and 7 subordinates. In LLA colonies alien males remained as a discrete group spatially separated in the cage. Female aliens were incorporated into the main colony. In all cases dominant male mice made more attacks on aliens as compared with familiar mice.     

Hostility in fantasy: A further test of the hypoglycemia-aggression hypothesis

In a recent investigation carried out among the Qolla Indians of Peru, Bolton (1973a) tested the hypothesis that hypoglycemia tends to produce high levels of individual aggressiveness. Glycemic condition was determined by the readings on a 4-hour glucose tolerance test performed on a sample of 54 adult males. Key informants then ranked these subjects on overt aggressiveness. A correlational analysis of the data supported the hypothesis that moderately hypoglycemic subjects would be more aggressive than the normoglycemic subjects. The present paper responds to questions raised about this study and describes the results of an additional test of the hypoglycemia-aggression hypothesis. The dependent variable in this follow-up study is fantasy aggression. Aggression scores were derived from Sentence Completion Test protocols for the same sample of subjects used in the first study. The results indicate a significant correlation between glycemic condition and aggression scores (Biserial, 0.57), thus providing further confirmation of the hypoglycemia-aggression hypothesis.     

Rank and reproduction among female langur monkeys: Aging and improvement (They're not just getting older,they're getting better)

An investigation of the social rank, reproduction, and ages of adult female Indian gray langur monkeys (Presbytis entellus) living in two colony social groups revealed that rank based on displacements is neither correlated with nor best predicted by female age or reproductive value. The hierarchy of female ranks is best conceptualized as a layered ranking system in which there are clusters of females of the same dominance rank forming layers within the structure. Statistical significance in frequencies of displacement differs between but not within these layered groups of females. Factors such as group composition, presence of uterine kin, reproductive state, and individual personality are hypothesized to predict changes in female rank far better than does reproductive value. Our data show that reproductive success increases with age. The infant survival record for the six oldest females in our colony was much better than for the five youngest adult females.     

Attack and defensive behaviors in the albino mouse

Attack by dominant male colony mice on intruders included chasing and lateral attack behaviors, while the corresponding intruder behaviors were flight, boxing, and checking. Both of these are similar to the attack and defensive behaviors of colony rats and intruders. However, mice did not show a significant constraint on bites to ventral areas, and the rat defensive behavior of lying on the back, which is effective because of this constraint, was rare; the corresponding “on-top” behavior of attackers was almost absent in mice. These findings strongly support the view that intraspecific attack and defensive behaviors, and target sites for bites, are interrelated factors facilitating effective but nonlethal agonistic interactions in muroid rodents.     

Violence and the disaggregated society

This paper reviews the evidence that social disaggregation is a major cause of destructive violence in non-human animal societies. The multifactorial theory of agonistic behavior is modified into a polysystemic theory which relates factors on each level to each other in an integrated model. As a result, it is suggested that disaggregation of systems on any level may lead to maladaptive violence. On theoretical grounds it is concluded that disaggregations of ecosystems and social systems are more probable and hence more dangerous than those of physiological and genetic systems. Applications of these findings to human affairs are discussed, both as explanations and as guides to positive action.     

NONCONTINGENT REINFORCEMENT: A FURTHER EXAMINATION OF SCHEDULE EFFECTS DURING TREATMENT

We conducted 2 studies to determine whether dense and thin NCR schedules exert different influences over behavior and whether these influences change as dense schedules are thinned. In Study 1, we observed that thin as well as dense NCR schedules effectively decreased problem behavior exhibited by 3 individuals. In Study 2, we compared the effects of 2 NCR schedules in multielement designs, one with and the other without an extinction (EXT) component, while both schedules were thinned. Problem behavior remained low as the NCR schedule with EXT was thinned, but either (a) did not decrease initially or (b) subsequently increased as the NCR schedule without EXT was thinned. These results suggest that dense schedules of NCR decrease behavior by altering its motivating operation but that extinction occurs as the NCR schedule is thinned. The benefits and limitations of using dense or thin NCR schedules are discussed.     

Intrafamily Aggression in Turkey: Frequency,Instigation, and Acceptance

Abstract

The present study was designed (a) to determine the frequency of aggression within different pairs of family members, (b) to define actions that may be construed as instigations of intrafamily aggression when committed by different members of the family, and (c) to investigate acceptance rates for different types of aggression from and toward different family members as reactions to different instigations. Questionnaires were administered verbally to 185 Turkish men and women between the ages of 14 and 75. The reported frequency of aggression was highest in mother-child relationships. Reported frequencies were higher for milder acts of aggression than for harsher acts. Content analyses of definitions of different actions that could be construed as instigations for aggression varied, depending on the person performing the act. Variations were consistent with power differences within the family and with gender stereotypes. The acceptance rate for intrafamily aggression was higher for verbal than for physical aggression and showed variations, depending on the nature of the instigation. Discussion focused on the relationship between intrafamily aggression and control.