Influences of social isolation during development on sexual behavior of the rat

Male and female rats were weaned at 14 days of age and raised in social isolation or with three other animals. At maturity the male isolates displayed less male sexual behavior than the socially reared Ss. Female isolates, after ovariectomy and injection with androgen, exhibited much less male sexual behavior than control females similarly tested. After being brought into estrus by injections of estrogen and progesterone, the female sexual behavior of female social and isolate Ss did not differ. Data were interpreted as indicating that social isolation during development deprives rats of critical experiences necessary for development of appropriate responses to social stimuli eliciting male copulatory behavior in both sexes.     

Resident rats’ aggression toward intruders

A study was performed in which attacks by four different types of “resident” rat (males housed with fertile females, males housed with sterile females, paired males, and isolated males) on six different types of intruder (isolated males, grouped males, castrated males, isolated females, grouped females, and ovariectomized females) were investigated. The objective was to study features of resident and intruder rats that would allow the designing of an aggression test that used a minimum of animals and produced a rapid behavioral response. In some combinations of residents and intruders, attack was generated within a 10-min test period. Isolated resident males attacked as much as males housed with females; however, paired rats showed only low incidences of attack. The fertility of the female partner did not influence the male’s aggressiveness. Most male attacks were directed towards like-sexed intruders. Only isolated males differentiated between the different treatment types of male intruder, attacking group-housed and castrated rats less intensely than isolates. Of the females, only those that were fertile produced significant amounts of attack behavior and almost exclusively attacked female intruders. Group-housed intruder females received more attacks than isolates. The results suggest optimal conditions for generating two models of attack behavior in the laboratory rat.     

Sex pheromones and aggressive behavior in male rats

Two experiments were performed to examine the relationships among the sexual cycle of the female, sex pheromones, and the agonistic behavior of male rats. Data suggest that the presence of an inaccessible sexually receptive female provokes increased intermale fighting. The present research investigated the possibility that a sex pheromone from the female mediates the change in male hostilities. In Experiment 1, a combination between-subject and within-subject design was used to expose half the males to the female by several sensory modalities. The other males were exposed to the female primarily by olfaction. In Experiment 2, a completely between-subject design was used to expose some males only to the soiled bedding of the female. The results suggest that olfaction is sufficient to increase the male’s aggressiveness in the presence of an estrous female, although additional sensory input, such as the female’s movements, may be necessary to produce the full aggression-inducing effect.     

Persistence of social investigatory behavior in the male rat: Evidence for long-term memory of initial copulatory experience

The duration of active social investigation by sexually mature male rats, following exposure to a novel conspecific, was investigated to assess the influence of former social experience. In Experiments 1 and 2, pretest social isolation of older males with extensive heterosexual experience and of younger males with limited heterosexual experience failed to affect their subsequent persistence in social investigation. Older and sexually experienced rats, however, engaged in significantly less investigatory behavior than did younger, sexually inexperienced males. Experiments 3, 4, and 5 demonstrated that this difference was associated with prior copulatory experience. A single copulatory series with either an intact female or a hormone-primed castrate female effected a significant and sustained decrease in social investigatory behavior. The results are interpreted as demonstrating a form of long-term memory for associations formed during initial copulatory experience.     

Male-female associations in the domestic guinea pig

Male courtship of nonreceptive females and male-male agonistic encounters were monitored daily for eight heterosexual groups of guinea pigs. Typically, one male (the associating male) accounted for much more courtship of a given female during her pregnancy than did any of the other males. Associating males were high ranking animals but were not always the group’s normal alpha male. Nonalpha associating males invariably ranked higher on the day of the female’s litter and postpartum estrus than their modal daily rank during her pregnancy. In 10 of the 18 cases, a nonalpha associating male took over the alpha position on the day of the litter. The courtship of females by associating males was found to differ from that by nonassociating males in that associating males displayed circling, rumping, swaying, and pursuit in a significantly higher percentage of the total number of courtship bouts.     

Vocalization correlated with self-induced changes in visual-auditory contact between mated Japanese quail

The emission of location calls, when visual separation and acoustical attenuation are caused by the animal’s own movements, is analyzed in this study. An animal could emit location calls at a fixed rate regardless of visual contact, but functional and energetic considerations suggest that location calls should occur infrequently when animals are in close visual contact. The results show that two calls, the staccato call and the cricket call, occur a greater proportion of the time when male and female Japanese quail are separated. The growl, a vocalization occurring in agonistic situations, was emitted more frequently when the animals were in close visual contact.     

Play-solicitation behavior in juvenile male and female rats

Play-solicitation and social investigatory behaviors were observed in male and female juvenile rats exposed to playful and nonplayful juvenile social stimuli. A nonplayful state was induced by treatment with scopolamine HBr. In Experiment 1, the play-solicitation behavior of males exposed to nonplayful stimuli was reliably greater than that of females; social investigation did not differ by gender. In Experiment 2, males and females were exposed to nonplayful male and female stimuli. Male subjects engaged in more soliciting than did female subjects, and male social stimuli were subjected to more soliciting than were female social stimuli. Experiment 3 compared the influence of varying social deprivation intervals on play soliciting by male juveniles. Although social investigation did not vary reliably with interval of social deprivation, play soliciting increased reliably with longer intervals of isolation. In Experiment 4, play-soliciting behavior of males exposed to nonplayful males correlated positively and reliably with play fighting behavior upon exposure to normally playful males. The results support the proposal that some specific behaviors functionally provoke interactive play fighting.     

Determinants of ejaculatory failure in the copulatory behavior of cactus mice (Peromyscus eremicus)

Although cactus mice,Peromyscus eremicus, typically resume copulatory behavior soon after attaining their first ejaculation, they rarely attain additional ejaculations. Experiment I was designed to determine the relative contribution of the male and female to this phenomenon of “ejaculatory failure”—the failure to attain ejaculation despite initiation of a series. Each of 18 male and 18 female cactus mice was tested in three conditions: once with a mated male paired with an unmated female, once with an unmated male paired with a mated female, and once with the original pairing retained. Ejaculatory failure was found to be primarily attributable to changes in the male. In Experiment II, it was found that the inhibitory effects of the first series are largely, but not completely, dissipated after 24 h. The first ejaculatory series appears to produce an elevation of the male’s ejaculatory threshold.     

Defensive attack behavior in male and female rats

Male rats in a restraining tube bit and wounded the snout of an anesthetized male conspecific as a direct function of the intensity of tailshock, with bites declining systematically in the time interval after shock. Female rats’ bites on a male rat were also dependent on shock, but did not produce wounds. When an anesthetized cat was presented to rats in the same situation, females bit and wounded the cat before shock was given, while the males again bit only in response to shock. These data were interpreted as indicating that male bites on both a conspecific and a predator fit the same defensive biting pattern. In contrast, females’ bites on a male rat are actively inhibited, while females’ bites on a predator are neither inhibited nor shock dependent: this latter finding may reflect the adaptive value (protection of the young) of attacking a predator before it hurts the female rat.     

Social learning and social transmission of foraging information in Norway rats (Rattus norvegicus)

Adult male Norway rats were tested in a first experiment to see whether foraging efficiency could be improved by social learning. Observers were placed in one of four conditions in which they were paired with demonstrators that either had or had not been previously trained to dig for buried carrot pieces, and in which the demonstrators either did or did not have carrot buried in the experimental enclosure. Observers in the group with trained demonstrators that did have carrot pieces buried in the experimental area during the observation period subsequently unearthed more buried carrot, did so more rapidly, and were generally more active than were the observers in the other three groups. In a second experiment, chains of transmission were established by allowing each observer to act as a demonstrator for the next naive observer. Enhanced levels of digging behavior were maintained across eight transmission episodes in three transmission groups relative to a no-transmission control group, the performance levels becoming stable after five transmission episodes at a level significantly above that of the control group. The study demonstrates that social learning and transmission mechanisms exist which might result in the diffusion of certain patterns of behavior through populations of Norway rats.     

How gender is constructed and experienced in the social world of the nursery school

This case study attempts to capture the way gender is constructed and experienced in the social world of the nursery school. It presents findings from a staff survey, structured and unstructured observations of one male’s and one female’s professional practice and one-to-one interviews with children aged three to four years. Despite practitioners’ reported intentions to challenge traditional notions of gender, construction of traditional gender distinctions was not problematised by staff and was upheld by comments of children. Children appeared to construct themselves in terms of gender stereotypes and were offered only limited alternative gender positions by the male and female practitioners.     

A comparison of the aversive and female attractant properties of urine from dominant and subordinate male mice

The urine of individual dominant and subordinate male mice was tested for male-aversive and female-attractant properties using dominant and subordinate male donors and Ss and estrous and anestrous female Ss in open-field tests. The results indicate (1) the presence of a factor in the urine of dominant males which proves aversive to both dominant and subordinate Ss, (2) the presence of a female attractant in the urine of dominant males, (3) naive females must be in estrous to respond positively to male urine. The results are discussed in terms of preputial and coagulating gland contents, androgen levels, and possible territorial functions.     

Behavioral control by stimulus components of an imprinting object

In the first of three experiments, ducklings that had received prolonged exposure to the visibly moving imprinting object subsequently suppressed ongoing distress vocalization both during brief presentations of the moving object and during brief presentations of its initially neutral stimulus components (i.e., its auditory and static visual features). Only presentations of the moving object were followed by priming aftereffects (namely, enhancement of distress vocalization over a baseline rate). In Experiment 2, weak, but reliable, priming effects were detected after very long presentations of the auditory and static visual features. Experiment 3 found that these features strongly suppressed low, but not high, rates of distress vocalization, while the visibly moving object strongly suppressed both high and low rates. These studies suggest that initially neutral features of an imprinting object acquire the same sort of behavioral control as is exerted by the object when it is in motion, but that this control is somewhat weaker.     

Environmental factors influencing the affiliative behavior of male and female rats (Rattus norvegicus)

Three experiments were conducted to investigate the influence of rearing and housing manipulations on the affiliative behavior of male and female rats. Animals were tested in same-sex pairs in an open field for time spent in contact and for socially facilitated activity. The results revealed a sex difference in both the degree and the form of affiliative behavior of rats. In general, males were more affiliative and more responsive to a second animal. Males engaged in more rough-and-tumble play, whereas females spent more time in social grooming. Housing conditions of adult animals and rearing conditions were found to influence the degree to which males engaged in male-like affiliative behaviors and females engaged in female-like affiliative behaviors. Social behavior appears to be a function of the interaction between the affiliative repertoire of the animals involved, the nature of the social stimulus, and the features of the environment.     

The past is present: The role of maltreatment history in perceptual,behavioral and autonomic responses to infant emotional signals

In the current study associations between parents’ experiences of childhood maltreatment and their perceptual, behavioral and autonomic responses to infant emotional signals were examined in a sample of 160 parents. Experienced maltreatment (both physical and emotional abuse and neglect) was reported by the participants and, in approximately half of the cases, also by their parents. During a standardized infant vocalization paradigm, participants were asked to squeeze a handgrip dynamometer at maximal and at half strength while listening to infant crying and laughter sounds and to rate their perception of the sounds. In addition, their heart rate (HR), pre-ejection period (PEP), and vagal tone (RSA) were measured as indicators of underlying sympathetic and parasympathetic reactivity. Results indicated that participants did not differ in their perceptions of the infant vocalizations signals according to their maltreatment experiences. However, maltreatment experiences were associated with the modulation of behavioral responses. Experiences of neglect during childhood were related to more handgrip force during infant crying and to less handgrip force during infant laughter. Moreover, a history of neglect was associated with a higher HR and a shorter PEP during the entire infant vocalization paradigm, which may indicate chronic cardiovascular arousal. The findings imply that a history of childhood neglect negatively influences parents’ capacities to regulate their emotions and behavior, which would be problematic when reacting to children’s emotional expressions.     

Sex differences in the emotional behavior of three strains of laboratory rat

Sex differences in the emotional behavior of three strains of rats were investigated, using a variety of measures taken during the initial 2 min of open-field exposure and after a loud bell had sounded. Animals were tested either in a clean open field or in one containing the odor of a same-sex conspecific. No general overall sex differences for a variety of measures associated with emotional reactivity were found, so the results did not support the theory that male rats are more “emotional” than females. Sex differences for particular measures associated with emotional responsiveness were found, but these varied with the strain, measure, and odor condition: The latter was found to be particularly important.     

Responses of sexually experienced and naive male rats to cues from receptive vs. nonreceptive females

In order to learn more about their reaction to the female sex attractant, 61 male Norway rats were given two-choice preference tests in which they reacted to cues from receptive vs. non-receptive females. In the first experiment, 16 heterosexually experienced males showed a reliable preference (p < .01) for receptive over nonreceptive anesthetized females, as did 15 naive males (p < .02) which later proved to be copulators. Ten naive males which later proved to be noncopulators showed no reliable preference for either type of female. In the second experiment, 15 naive males which later proved to be copulators showed no reliable preference for the odors from receptive vs. nonreceptive females. From these experiments, we conclude that naive males which later prove to be sexually vigorous are attracted to the composite bodily cues from receptive females, and that this attraction is not mediated by olfactory cues alone.     

Attraction to mobile and immobile conspecifics

Male and female laboratory rats invariably investigate a novel conspecific placed in their home cages. In Experiment 1, mature male rats were exposed in their home cages to active and inactive juvenile males. Inactive juveniles were pretreated with haloperidol to induce behavioral stasis in a normally upright, quadrupedal stance. In repeated daily observations, males exposed to active juveniles displayed significantly longer intervals of investigation than did males exposed to inactive juveniles. In Experiment 2, mature males and females were repeatedly exposed to active and inactive castrate females. Males investigated significantly longer than did females, active female castrates were investigated significantly longer than were inactive female castrates, and sex of subject interacted significantly with activity-nonactivity of the social stimulus animal. In Experiment 3, mature males and females were repeatedly exposed to active and inactive castrate males. Males investigated significantly longer than did females, active male castrates were investigated significantly longer than were inactive male castrates, and sex of subject interacted significantly with activity-nonactivity of the social stimulus animal. The results demonstrate that sexual dimorphism in persistence of social investigation may be interpreted as a sex difference in response to normal movement cues of a stimulus complex characterizing a conspecific.     

妇女运动爆发前的俄罗斯女子教育

从基辅罗斯时期到19世纪六十年代妇女运动爆发前,俄罗斯女子教育经历了近千年的发展与衍变历程,总体上可以分为以下三个时期:中世纪若有若无的女子教育,完全受惠于自发参与到教育实践中来的上层社会女性;18世纪,当政者意识到女子教育对国家发展的重要性,由统治者主导的教育改革不但将女子教育提上日程,而且通过引进西欧教育模式大力发展本国女子教育;19世纪上半叶,女子教育逐渐从整个教育体系中分离出来。长期以来,俄国女子教育一直隐藏在男子教育的光环之下,其教育内容则始终围绕当权者对妇女贤妻良母的角色定位而展开,与现代意义上的女子教育尚存在一定距离。     

Neglected fathers: Limitations in diagnostic and treatment resources for violent men

In its examination of violent activity within the family, current literature assumes a “pecking order” exists: Larger and stronger family members attack those who are smaller and weaker. Adult males are usually studied as primary maltreaters of spouses, while females are considered mainly responsible for physically abusive behavior with children. Use of this perspective has led to neglect of male abusers, who injure half of the mistreated children in the United States. Through assessment of 66 studies of child abuse published during a 5-year period, this paper documents the lack of attention abusive fathers have received. Twenty-eight of these studies included only mothers, while two dealt exclusively with fathers. Most of the 36 remaining two-parent studies did not discuss sex differences. No diagnostic categories consistently differentiated male from female abusers. No study discussed specialized treatment needs of women and men. This survey suggests that the therapeutic field considers the child's mother the primary responsible parent, even though she may not be the perpetrator of violence in the family. As a result, inadequate treatment resources have been made available to maltreating fathers. The survey points to the need for much more comprehensive research comparing male and female maltreaters.