Unfamiliar Pairs Research Articles

No Pain, No Gain: Bordering the Hungry New World Order

The late-modern discourses of female slenderness and free-market reform share striking rhetorical similarities. Furthermore, their corporeal effects are quite similar. The historical coincidence of their deployment is no accident; rather, they represent two gestures of a (re)figured late-modern hegemonic practice that feeds, ultimately, on hunger. By juxtaposing and critically interrogating these two discursive practices, it is apparent that a familiar binary opposition—thin/fat—was substituted for an unfamiliar pair—adjusted/unadjusted. This discursive swap drew upon a long history of filtering between bodies and economies, and acted to naturalize a new disciplinary phase in late modernity. This phase is unsurprisingly profoundly gendered. It is also spatialized via connection with another binary chain: First World/Third World, North/South, West/East, developed/underdeveloped, here/there. However, the relationship of these two binary chains is contradictory, and this has given rise to a contestation of power that coalesces, literally and figuratively, around borders.

Solitary is not Asocial: Effects of Social Contact in Kangaroo Rats (Heteromyidae: Dipodomys heermanni)

Social interactions in solitary animals, such as Heermann’s kangaroo rat (Dipodomys heermanni), have been little studied. In three experiments, the effect of social housing on levels of aggression and maintenance of estrous cycling was studied as part of a captive breeding program for an endangered form of this species. Expt 1 demonstrated that mixed‐sex pairs of rats that were neighbors in social housing were no friendlier during staged encounters than unfamiliar pairs also housed socially. In expt 2, rats that had been isolated for several months were transferred to social housing and paired at weekly intervals with an opposite‐sex neighbor. Initial encounters were highly aggressive and socialized partners retreated from previously isolated rats more often than vice versa, regardless of sex. By the third week, encounters resembled pairings of fully socialized rats, as in expt 1. Thus, social exposure may produce a general socializing effect rather than promote familiarity between specific individuals. In expt 3, the clear, perforated barriers that separated rats in social housing were replaced with solid, opaque barriers for 6 wk. Estrous cycle length immediately doubled and cycles of most females were disrupted for months. Taken together, the results reveal the influential role of social contact in this solitary species and highlight the need for more such work both for developing comprehensive theories of sociality and for guiding captive propagation efforts.

Playful defensive responses in adult male rats depend on the status of the unfamiliar opponent

Adult male rats reared as pairmates from weaning were tested in a neutral arena with both members of another pair (one at a time). The unfamiliar pairs were found to engage in play fighting, although they were more likely to escalate the encounter into serious fighting than were pairs of familiar rats. Based on their within-home pair behavior, each pairmate was designated as a dominant or a subordinate. When the test encounters between unfamiliar males were analyzed with regard to whether the pairings consisted of two dominants, two subordinates, or a mixed pair, the pattern of play fighting was found to be attenuated. Both dominants and subordinates were more likely to initiate playful encounters, to respond defensively during these encounters, and to do so using adult-typical tactics of defense when paired with an unfamiliar rat that was dominant in its home cage. The mechanisms by which the home status of unfamiliar male rats can be identified by another male are discussed, particularly with regard to the role that play fighting may serve for this function. It is concluded that the data support the hypothesis that play fighting can be used by adult rats for social testing, which in this case seems to involve ascertaining the opponent's fighting capability. Aggr. Behav. 25:141–152, 1999. © 1999 Wiley-Liss, Inc.

Resolution of agonistic conflicts in dyads of acquainted green swordtails ( Xiphophorus helleri): a game with perfect information

Conflict resolution of acquainted opponents was compared to that of unacquainted ones in Xiphophorus helleri males. Under the Familiar condition, the 2 males which met had settled contest against each other in a previously staged encounter in another aquarium. Thus one opponent was previously the dominant pair member, the other its subordinate. Under the Unfamiliar condition, 2 males met which were not acquainted with each other but had independently undergone previous experience of victory or defeat. We tested the hypothesis that familiar pairs would conform to some behavioural predictions of an asymmetrical game with perfect information. As for unfamiliar pairs, being imperfectly informed of asymmetries at contest onset, they would have to acquire information on these during the course of interaction ( asymmetrical game with assessment) or alternatively would have to persist for a certain time or cost ( war of attrition). All expectations derived from an asymmetrical game with perfect information applied to familiar pairs but not to unfamiliar ones. In familiar pairs, all previous roles were reinstated without any escalation. Though previous winners predominantly defeated previous losers under both conditions of cognizance, this difference was more extreme in familiar dyads than in unfamiliar ones. This suggests that the respective roles were less clearly identified in the latter. The costs of conflicts, both in terms of aggressive behaviours used and in time, were also higher in unfamiliar pairs than in familiar ones. Unacquainted individuals required a longer period to assess each other. In addition, they had to rely on more pugnacious behaviour to settle disputes in comparison to acquainted pairs. As expected also, familiar pairs being already cognizant of initial respective roles were more characterized in terms of the behavioural patterns typical of each of these roles. Differences between ultimate winners and losers were clearer in acquainted pairs and appeared earlier during conflict. It was also possible earlier during contest to discriminate and predict ultimate winners from losers of acquainted pairs using behavioural interactions. In unacquainted pairs, ultimate winners could be forecasted using multivariate discriminant analyses, mainly by their offering resistance to future losers. A `war of attrition' did not fit to unacquainted pairs.

Role of Familiarity in Structuring Male–Male Social Interactions in the Cockroach Gromphadorhina portentosa (Dictyoptera: Blaberidae)

We examined the influence of prior social experience on the outcome of agonistic interactions between male Madagascar hissing cockroaches, Gromphadorhina portentosa (Schaum). Males were placed randomly in pairs and allowed to form stable dominance-subordinance associations (original pairs). Two types of social conditions were then examined. Treatment pairs were composed of either familiar males (the males were re-paired with the same male that they had interacted with previously) or unfamiliar individuals (males were paired with a male that they had not interacted with previously). Males in familiar pairs maintained their rank during subsequent interactions. However, males in unfamiliar pairs lost their rank, indicating that familiarity of the opponent and not past experience of winning or losing an encounter determined the outcome of interactions. We also compared the behavior of individual males in the treatment groups with their behavior in the original pairings. Previously dominant males decreased their levels of aggression and hissed less when interacting with unfamiliar opponents. Previously subordinate males were more aggressive and hissed more in unfamiliar pairs. As a result, overall levels of behavior displayed in pairs of males did not differ. Aggression and hissing appear to be important in the maintenance, rather than the establishment, of relationships between G. portentosa males. We also discuss the possibility that agonistic hissing functions in individual discrimination rather than as a status cue.

Effects of familiarity on the outcome of translocations, I. A test using saddlebacks Philesturnus carunculatus rufusater

Translocation, the intentional release of a species in a new location, plays an important role in the conservation of endangered species. Consequently, there is a critical need for research on factors affecting the outcome of translocation attempts. This study addresses the hypothesis that founder groups will do better if they are made up of individuals that are familiar with one another. The hypothesis is based on research on birds showing that familiarity between mates and neighbours leads to lower aggression and higher reproductive success. Our test involved a translocation of the North Island saddleback Philesturnus carunculatus rufusater, a New Zealand forest bird restricted to islands free of mammalian predators. We created two founder groups of 18 birds each, one made up of birds from a single small forest patch, and including five known pairs, and the other a mixture of birds from several patches, with no pairs. We released the groups in different parts of an island, and assessed the effects of familiarity on survival, dispersal, pair bonding, and reproduction. The two groups showed similarly high survival, and both dispersed widely. Pair bonds formed more quickly among the familiar birds, even though only one of the five original pairs stayed together after translocation. While pairing among unfamiliar birds tended to be delayed, they achieved a similarly high rate of pairing by the start of the breeding season, and reproductive output was similar for familiar and unfamiliar pairs. We therefore found no evidence that using familiar individuals would improve the outcome of bird translocations. We note that familiarity could be more important with other species and/or in other circumstances. However, we also note the potential costs of using familiar individuals.

Social tension and displacement activities in familiar and unfamiliar pairs of Java monkeys

(1990). Social tension and displacement activities in familiar and unfamiliar pairs of Java monkeys. Ethology Ecology & Evolution: Vol. 2, No. 3, pp. 327-327.

Patterns of behaviour during postpartum oestrus in prairie voles, Microtus ochrogaster

Social and sexual behaviour during postpartum oestrus in prairie voles was monitored using time-lapse videotaping over a period of at least 24h. Behaviour was measured as a function of the familiarity and social history of the male partner and as a function of the presence or absence of pups. In general, postpartum oestrus was shorter than male-induced oestrus. When pups remained with the pair, the duration and frequencies of copulatory interactions were further reduced. In familiar pairs mountlordosis bouts were more frequent, and durations of male autogrooming and side-by-side contact were longer than in unfamiliar pairs. All pairs successfully reproduced and litter size among groups was similar, even then the frequency of sexual activities was very low. These results suggest that in monogamous species, such as prairie voles, the social history of the pair was well as female reproductive status are strong determinants of sexual and social interactions that occur during postpartum oestrus.

Social Tension in Familiar and Unfamiliar Pairs of Long-Tailed Macaques

The behavioural responses of monkeys to the pairing with familiar and unfamiliar individuals were analysed in order to test whether differences in social tension were related to different patterns of affiliation. Social tension was derived from the frequency of displacement activities. Ten familiar pairs (the F group) and 20 unfamiliar pairs (the UF group) of adult female long-tailed macaques (Macaca fascicularis) were observed in a two-hour test. The UF group was divided into two subgroups on the basis of the establishment of clearcut dominance relations within the pairs (as revealed by bared-teeth displays). Unfamiliar pairs showing clearcut dominance relations (the UFa subgroup) did not differ from the F group in terms of grooming exchanged and displacement activities. Unfamiliar pairs without clearcut dominance relations (the UFb subgroup) showed less grooming and more displacement activities. A delay in the onset of allogrooming due to unresolved dominance relations was responsible for the differences in social tension between the different monkey pairs. The results of this study suggest that unfamiliarity between the monkeys is not a good predictor of social tension if the patterns of behavioural interactions between the individuals are not taken into account.

Comparative studies of social behavior in Callicebus and Saimiri: Behavioral and physiological responses of established pairs to unfamiliar pairs.

Comparisons were made of the behavioral and physiological responses of heterosexual pairs of two closely related New World primates, Callicebus moloch and Saimiri sciureus, to confrontations with unfamiliar pairs. Subject pairs were exposed to strangers in two situations differing in the presumed degree of arousal they imposed: obligatory (full visual exposure) and facultative (one part of the test cage allowed visual withdrawal). Behavioral reactions were evaluated employing frequencies of affiliative behaviors, agonistic behaviors, and spatial distribution. Physiological reactions were evaluated employing heartrate and plasma corticosteroid levels. Callicebus males and females were similarly affected by unfamiliar pairs. Both sexes behaved agonistically towards strangers; pairmates drew closer together and behaved in a coordinated fashion. Display behaviors declined, and spatial withdrawal increased over time. Heartrate in both sexes increased during confrontations, particularly during obligatory exposure. The reactions of Saimiri to strangers differed between the sexes. Males reacted agonistically toward unfamiliar conspecifics, as reflected in displays and spatial adjustments. In contrast, females showed a strong attraction to unfamiliar females. Despite the sex differences in behavior, heartrate did not differentiate confrontation conditions clearly in either sex. Plasma cortisol measures failed to differentiate between experimental conditions in either species.

Familiarity and Inbreeding Avoidance in the Gray-Tailed Vole (Microtus canicaudus)

The role of familiarity in inbreeding avoidance was tested in captive gray-tailed voles ( Microtus canicaudus ) in the laboratory. Individuals that were familiar with one another, regardless of relatedness, produced fewer litters than unfamiliar pairs. There were no apparent differences in litter size or pup viability between siblings versus non-siblings. Recognition of kin was based on familiarity. Individuals that were separated for 5 or 12 days from potential partners with whom they had been reared retained their mating avoidance. In the held, familiarity of voles may increase in low density populations and reproductive behavior may decline as a result. Thus, familiarity, kin recognition, and inbreeding avoidance may play important roles in vole population cycles.

How Stranger Encounters of Common Marmosets (Callithrix jacchus jacchus) Are Influenced by Family Members: the Quality of Behavior

The initial confrontations of 33 previously unfamiliar pairs of common marmosets were observed. Four types of pairs were used (alpha males/alpha females; alpha males/subdominant females; alpha females/subdominant males; subdominant males/sub-dominant females). Each dyad was tested in five different experimental conditions: (1) isolation of both individuals from their families, unilateral encounters in which either the (2) male’s or the (3) female’s family was visible to the dyad through a one-way screen, and interactive encounters in which either the (4) male’s or the (5) female’s family was present behind a wire screen. Pairs which included alpha females exhibited no affiliative, practically no sexual, but high levels of aggressive behaviors. Pairs which included subdominant females exhibited affiliative, high levels of sexual, and practically no aggressive behaviors. Behavior was reduced qualitatively as well as quantitatively with increasing presence of the families. Possible functional aspects of the results are discussed.

Etude des interactions sociales entre male et femelle chez la Genette (Genetta genetta L.): Relations entre marquage olfactif et agression

Abstract and SummaryStudy on Social Interactions between Male and Female Genets (Genetta genetta L.): Relations between Scent Marking and Aggression The aim of this work was to study the relations between marking behaviour and aggression in genets (Genetta genetta L.). Observations on social interactions were made on a socially stable pair and during encounters between unfamiliar pairs. In the first case, there appeared to be a relationship between marking activity in the male and aggression. During aggression periods, marking with the ano‐urogenital region increased in the male and decreased in the female. Another striking variation concerned flank rubbing and hindleg rubbing. In both male and female these marking frequencies increased significantly during aggression periods and flank rubbing was modified by visual cues. Data recorded during encounters between unfamiliar pairs (one male being introduced in a female's cage) showed that agonistic behaviours were released through visual cues in females and olfactory cues in males. The same changes in marking frequencies were observed. These results also showed that ano‐urogenital marking was inhibited in females during aggression periods. The adaptative significance of these phenomena is discussed.

Experimental study on sexual behavior between mother and son in Japanese monkeys (Macaca fuscata)

A mother, her adult son, four adult males and six adult females from a free-ranging group at Katsuyama were paired in a cage in the sexual seasons from 1976 to 1980. The paired subjects were classified into the following three types: mother and son, familiar pairs and unfamiliar pairs. The familiar pairs consisted of monkeys who had been in the Katsuyama group until about six months before the experiment. The unfamiliar pairs consisted of monkeys who had not met each other at all or who had not met each other for more than eight years before the experiment. Serial mounts which terminated with ejaculation occurred in nine of ten unfamiliar pairs, four of five familiar pairs, but there were none between the son and mother. The son and mother did not appear to be sexually aroused between themselves, although they were sexually active to other partners. However, on rare occasions, the son mounted singly on the mother, and on one occasion he ejaculated. Their interaction did not change essentially during the three years. The son rarely mounted serially on a female who had a close relationship with his mother.

The role of individual recognition by odors in the social interactions of the Mongolian gerbil (Meriones unguiculatus).

This study attempts to determine the importance of individual recognition by odors in the social interactions of male Mongolian gerbils (Meriones unguiculatus). The first experiment tested the effects of anosmia on social interactions. Twentyfour pairs of male gerbils were divided into two groups (experimental and control). Experimental animals were made anosmic by bathing their nasal mucosa with 7% solution of ZnSO4. Control animals were treated with distilled water. Following treatment, control and experimental animals were tested with both familiar and unfamiliar conspecifics, and the frequency and types of social behaviors were compared. The results showed that anosmic animals apparently cannot distinguish between familiar and unfamiliar conspecifics and, therefore, that they treat all other gerbils in the same manner that they treat familiar animals. Control animals, on the other hand, showed significant differences in the frequency and types of behaviors directed towards familiar and unfamiliar conspecifics. The second experiment tested the effects of unfamiliar odors on social behaviors. Twelve pairs of familiar male gerbils were tested under three conditions : with soiled shavings from their own home cage (own familiar odors), with clean shavings, and with soiled shavings from the cage of an unfamiliar pair of conspecifics (unfamiliar odors). The results showed that gerbils can detect unfamiliar conspecific odors and that the presence of such odors can affect the social behaviors of a pair of familiar animals. Pairs of familiar gerbils showed a high frequency of social interactions when in the presence of their own familiar odors, but a reduced frequency when tested with unfamiliar conspecific odors or with clean shavings. It is suggested that this decrease in social behaviors could have been due to changes in levels of arousal or to competing exploratory responses. These experiments thus demonstrate that individual differences in the biological odors of the Mongolian gerbil play an essential role in the recognition of individuals and in the normal pattern of social behaviors of this species.

Differential effects of familiarity on judgments of sameness and difference

Ss indicated whether pairs of simultaneously presented objects were “same” or “different.” In Experiments 1, 2, and 3 the stimuli were pairs of letters, and familiarity was manipulated by showing the letters in either an upright or an upside-down orientation. In Experiments 4 and 5 the stimuli were pairs of trigrams, and familiarity was manipulated either by rotation or by selection according to rated meaningfulness. Analysis of reaction times indicated that familiar pairs were responded to more quickly than were unfamiliar pairs; however, this was true only for “same” judgments, not for “different” judgments. In addition, Experiment 3 indicated that familiarity influenced discrimination accuracy under conditions of tachistoscopic exposure. Finally, in Experiment 6 an effort was made to disentangle the effects of meaningfulness from the effects of pronounceability. The present results stand in contrast to previous research using perceptual comparison tasks, since the earlier work failed to indicate any effect of familiarity.

Stimulus novelty as a factor in the intraspecific pain-associated aggression of domesticated rats

Familiar and unfamiliar pairs of male Sprague-Dawley rats were exposed to ascending and descending series of shocks of constant intensity and varying duration. It was found that, while unfamiliar pairs exhibited significantly more aggression than did familiar pairs when subjected to short-duration shocks (.05 and.1 sec), there was no difference between the groups at longer shock durations (.2,.3, and.5 sec).

Neuroticism and hypertension in an out-patient population

When playing, rats emit 50-kHz calls which may function as play signals. A previous study using devocalized rats provides support for the hypothesis that 50-kHz function to promote and maintain playful interactions (Kisko et al., 2015). However, in that study, all pairs were cage mates and familiar with each other’s playful tendencies that could have attenuated the role of play signals. The present study uses unfamiliar pairs to eliminate any chance for such attenuation. Four hypotheses about how 50-kHz calls could act as play signals were tested, that (1) they maintain the playful mood of the partner, (2) they are used to locate partners, (3) they attract play partners and (4) they reduce the risk of playful encounters from escalating to serious fights. Predictions arising from the first three hypotheses, tested in juveniles, were not supported, suggesting that, for juveniles, 50-kHz calls are not facilitating playful interactions as play signals. The fourth hypothesis, however, was supported in adults, but not in juveniles, in that unfamiliar adult males were more likely to escalate playful encounters into serious fights when one partner was devocalized. These findings suggest that vocalizations at most have a minor role in juvenile play but serve a more central role in modulating adult interactions between strangers, allowing for the tactical mitigation of the risk of aggression.

Social Facilitation and Allelomimetic Behavior in Dogs

1. This experiment represents an attempt to distinguish effects of social facilitation which may be caused by mutual mimicry of goal-directed behavior, and those which may be caused by competition. 2. Unfamiliarity should interfere with mutual mimicry but should intensify competition. 3. Sixteen dogs of five different breeds were run in familiar and unfamiliar pairs as well as alone. 4. Dogs run repeatedly with the same unfamiliar animal showed no important differences in either mutual mimicry or social facilitation as compared with runs with familiar animals. 5. Dogs run with a. different animal on each day showed lessened mutual mimicry and social interference amounting to 73 %. 6. It is concluded that the results are consistent with the hypothesis that one factor which may produce social facilitation is mutual mimicry of goal-directed behavior, and that this factor may act independently of competition. 7. As a further hypothesis, it is proposed that this factor may exist in any species which shows allelomimetic behavior, and that it may modify the effects of competition in such species. 8. Certain comparisons with human situations are discussed.