Dyadic Encounters Research Articles

Production of acoustic signals during aggression in Coosa bass, Micropterus coosae

Although sound production has been described for sunfishes, it is previously unknown for basses, both groups of fishes in the family Centrarchidae. We document production of acoustic signals during aggressive encounters in Coosa bass, Micropterus coosae. During dyadic encounters, presumptive winners of contests produced sounds associated with a variety of behaviors, including chases, lateral displays, circle swims, nudging, jerking and during post aggression, while fish were stationary. These sounds are low-frequency, non-harmonic and consist of one to 41 separate pulses. In most trials larger fish won contests, regardless of territory ownership (which fish was put into the test tank first) and size difference.

Body size and fat reserves as possible predictors of male territorial status and contest outcome in the butterfly Eumaeus toxea Godart (Lepidoptera: Lycaenidae)

We used adults of the butterfly Eumaeus toxea for two purposes—description of male territorial behavior and investigation of whether body size and muscle fat re- serves correlated with social status (resident or intruder) and the probability of winning a territorial contest in dyadic encounters. Males perched in places near cycads (Zamia furfuracea), where females lay eggs. Resident males (those with faithfulness to the same site for several days) used two types of flight of different duration, short (ca. 5 s) and long (ca. 17 s), against male conspecifics. Because of this dif- ference the latter were regarded as true contests. Males that copulated were residents and were also larger than males not observed in copulation. Residents and winners of contests were larger and fatter than intruders (males entering the site that faced a resident with a long-lasting flight) and losers of contests, respectively, possibly because these last two categories of male were individuals with already exhausted energy stores. Body size and fat reserves seemed to correlate with status for resident and intruder males but not for winner and loser males. This possibly means that body size reflects male energy condition. This is supported by the fact that large, resident males are con- fronted in short contests, in contrast with small, resident males. Our study suggests that the role of size and fat reserves during contests cannot be discounted in butterflies.

Female feeding priority in bonobos, Pan paniscus, and the question of female dominance

The question of whether bonobos show feeding priority and female dominance has been proposed and examined, both in the wild and in captive studies, with differing results. The relationship between female dominance and female feeding priority has been best studied in prosimian primates. These studies use established criteria of females consistently evoking submissive behavior from males in dyadic encounters for determining female dominance. Although the relationship is complex, female dominance in prosimians is associated with preferential access to food. Data from studies of wild habituated bonobos in the Lomako Forest, Democratic Republic of the Congo, are examined for evidence of both female feeding priority and female social dominance using similar criteria as used for prosimians. Bonobos showed evidence of female feeding priority in small, but not in large, food patches. Male-male competition for mating opportunities at the start of the food bout was related to some, but not all, differences in time spent feeding between the sexes. Female dominance similar to that seen in prosimians was not observed in these bonobos. Males were consistently dominant in dyadic interactions. Female feeding priority with male dyadic social dominance implies that male deference during feeding cannot be excluded as one explanation of interpretations of female dominance in bonobos. Additionally, dominance of male bonobos by females appears to require the presence of female coalition partners. As in other primates with female feeding priority, bonobo females express this trait where food is economically defendable. Unlike prosimians, however, bonobo female feeding priority may result from male deference and the importance of female coalitions in nondyadic interactions.

The Clinical Encounter and the Problem of Context

The encounter between professional and patient is one of the basic units of analysis in the field of ‘medical’ sociology. From the very beginnings of the sociological investigation of medical practice it has been conceived as a dyadic encounter, defined by asymmetries of power, the negotiation of rational and authoritative scientific knowledge, and private, proximal, relations. This article argues for a more dynamic theoretical vision of the clinical encounter: one that shifts attention away from a Parsonian ‘paradigm’ of professional–patient interaction towards a perspective that incorporates the systemic changes that late modernity brings to medicine.The clinical encounter is no longer the dyadic system envisaged by Parsons, and his theoretical perspective–which has played an important part in framing sociological accounts of the practice of medicine – now needs to be reframed in relation to the organizing impulses of contemporary corporate professional practice.

Effects of previous interactions and sex on over-marking in meadow voles

AbstractThe effects of winning and losing on over-marking behaviour of mammals, a behaviour associated with competition, are not known. The current study tests the hypothesis that after having a staged dyadic encounter with a same-sex conspecific, individuals adjust the proportion of scent marks they use to over-mark the marks of same-sex conspecifics. Female meadow voles that won their encounter used a higher proportion of their marks to over-mark the marks of female conspecifics than did females that either lost their encounter, were evenly matched, unfamiliar, or had no previous paired encounter. Females that lost their encounter used a lower proportion of their marks to over-mark those of female conspecifics than did females that either won their encounter or females that were evenly matched, unfamiliar, or had no previous paired encounter. Females that were evenly matched, unfamiliar, or had no previous paired encounter used a similar percentage of marks to over-mark those of another female. Male meadow voles, however, independent of whether they won, lost, were evenly matched, unfamiliar, or had no previous paired encounter used a similar proportion of marks to over-mark those of male conspecifics. The role of over-marking and the effects of previous social experience are discussed.

Influence of female-biased sexual size dimorphism on dominance of female Townsend’s chipmunks

Female-biased sexual size dimorphism (SSD), a condition common in North American chipmunks, occurs when females are larger than males in a species. We examined the influence of body size on dominance of captive female Townsend’s chipmunks ( Tamias townsendii Bachman, 1839), a species that exhibits female-biased SSD, in all-female and mixed-sex dyadic encounters. In all-female dyads, large female chipmunks were more frequently dominant over small female opponents. In mixed-sex dyads, large females were always dominant over small males. Female-biased SSD in Townsend’s chipmunks appears to indirectly allow large females to more frequently dominate small female and male conspecifics. Greater dominance could increase reproductive success of large female chipmunks by increasing access to resources.

Experience-Based Agonistic Behavior in Female Crickets, Gryllus bimaculatus

Fighting behavior in male crickets is already well described, and some of the mechanisms underlying aggression and aggressive motivation have already been revealed. Much less is known about female/female interactions. Here, we report that adult female crickets that had been isolated for several days readily entered into agonistic interactions with conspecific individuals. Characteristic dyadic encounters between isolated females escalated in a stepwise manner and were concluded with the establishment of a dominant/subordinate relationship. For 15 to 30 minutes following an initial fight, former subordinate females showed a dramatic change in agonistic behavior. If they were paired with the former dominant opponent during this interval, a significant majority did not enter into any aggressive interaction but instead actively avoided the opponent. A similar experience-based and time-dependent increase in avoidance was observed when former subordinate females were paired with unfamiliar naïve opponents. However, when faced with an unfamiliar subordinate individual in the second encounter, no such increase in avoidance behavior was observed. We propose that the observed changes in the behavior of former subordinate females are the consequence of a change in the general state of arousal and of the recognition of dominance status, but not of individual recognition. The fact that former dominant individuals did not show similar experience-based changes in agonistic behavior suggests that dominant/subordinate relationships between pairs of female crickets are maintained mainly by the behavior of subordinate individuals.

Intergroup Attitudes of European American Children Attending Ethnically Homogeneous Schools

Intergroup attitudes were assessed in European American 1st-grade (M=6.99 years, SD=0.32) and 4th-grade (M=10.01 years, SD=0.36) children (N=138) attending ethnically homogeneous schools to test hypotheses about racial biases and interracial friendships. An Ambiguous Situations Task and an Intergroup Contact Assessment were administered to all participants. Unlike previous findings with European American children attending heterogeneous schools, children rated minority perpetrators more negatively than majority perpetrators, and friendship as less likely when a minority than a majority perpetrator was portrayed. These findings suggest that intergroup contact contributes to racial bias in children's interpretations of peer dyadic encounters and to judgments about interracial friendships.

Seasonal changes in chronic social interactions and physiological states in female rat-like hamsters ( Tscheskia triton)

We examined the behavioral characteristics and physiological states related to solitary lifestyle and dominant–subordinate relationships in female rat-like hamsters ( Tscheskia triton), formerly known as Cricetulus triton. Wild adult hamsters were captured and caged singly in the laboratory during the non-breeding and breeding seasons. The experimental hamsters were subjected to 5 min staged dyadic encounters every day for 28 consecutive days by pairing two unfamiliar and weight matched females in a neutral arena. Aggressive behavior, defense and flank marking were quantified everyday within the first week and once each week during the last 3 weeks. Animals were then autopsied and their physiological and reproductive state assessed. Our results suggested that dominant–subordinate relationships could be established especially in non-breeding conditions, where the dominant displayed higher aggression and flank marking, and lower defense than its opponent. The breeding females followed this pattern except there was no difference in aggressive behavior, between the partners. The repeated encounters did not appear to reduce aggression or lead to amiable behavior or bonding. At the end of the experiment breeding females exhibited higher levels of serum estradiol, progesterone and corticosterone than non-breeding females. Both dominant and subordinate females in non-breeding condition had atrophied ovaries and uteri, whereas both dominant and subordinate females in breeding condition had hypertrophied ovaries and uteri. Non-breeding females possessed heavier and thicker flank glands than breeding females did. Dominant females displayed longer or thicker flank glands than subordinate did. Thus, our data suggest that the behavioral traits observed in our experiment support the solitary lifestyle of adult female rat-like hamsters and physiological state show some differences between social ranks or in both seasons.

Interspecific social interactions and behavioral responses of Apodemus agrarius and Apodemus flavicollis to conspecific and heterospecific odors

The social interactions between Apodemus agrarius and A. flavicollis, and their behavioral responses to conspecific and heterospecific odors, were studied in male–male and female–female interspecific dyadic encounters, and an attraction–avoidance test was used in order to clarify the behavioral mechanisms which control their relationships in wild populations. The experiments were carried out at the beginning and at the end of the breeding season—in spring and in autumn. In spring the aggressiveness was higher than in autumn. Males of both species showed attraction to conspecific odors from the opposite sex, while the females were indifferent. In autumn both males and females displayed attraction to conspecific odors from the same sex. However, mice of both species showed avoidance to heterospecific odors from the same and the opposite sex in spring, and indifference to heterospecific odors from the same and the opposite sex in autumn. Based on these findings, it could be assumed that the patterns of social interactions and responses to conspecific and heterospecific odors undergo seasonal changes in their life cycle. Probably the avoidance response to heterospecific odors could serve as a spacing mechanism to avoid aggressive encounters between A. agrarius and A. flavicollis in syntopic habitats during the breeding period.

First Record of Polydomy in a Monogynous Ponerine Ant: A Means to Allow Emigration Between Pachycondyla goeldii Nests

The ponerine ant Pachycondyla goeldii is a monogynous (i.e. one queen per colony) arboreal species that colonizes pioneer areas. Founding queens and first generation workers initiate their own ant garden by building a cardboard-like structure into which epiphyte seeds are integrated. Following the growth of the epiphyte, the colony establishes its nest within the root system. This particular nest-building behavior is crucial in an environment where suitable nest sites are rare. Nevertheless, the slow growing process of ant gardens does not allow this species to readily evacuate and find another refuge in the advent of an attack by a predator or worsening climatic conditions. Previous field studies of P. goeldii were performed after forest destruction and subsequent colonization by P. goeldii. As a result, the colonies studied where relatively young and monodomous (i.e. one nest per colony). Our study of nest composition, worker exchanges between ant gardens in the field, and dyadic encounters shows that mature colonies of P. goeldii are polydomous (i.e. multiple nests per colony). In ants, the association of polydomy with monogyny has infrequently been reported. To our knowledge, P. goeldii represents the first record of a Ponerinae exhibiting both these particular characteristics. Our field and laboratory experiments suggest that polydomy is adaptively advantageous in coping with the microclimatic instability of pioneer areas by providing colonies with easily accessible nests.

Modeling the acquisition of social rank in crayfish: winner and loser effects and self-structuring properties

Summary Stable hierarchical structures within groups of crayfish emerge from a series of dyadic encounters among its members. A modeling approach was used to explore the progression in fighting success of individual entities under different behavioral scenarios and the respective outcomes were fitted to empirical data. Changes in the relative magnitude of winner and loser effects influenced the divergence of hierarchical ranks: a few high-ranking despots rapidly emerged when winner effects were dominant, an excess of loser effects quickly produced individuals of distinctly low rank, while a balance of winner and loser effects produced a more gradual divergence of ranks. Comparison with empirical data from the formation of social group structure in crayfish indicated a greater importance for loser effects.

Concurrency and Commitment: Network Scheduling and Its Consequences for Diffusion1

ABSTRACT Network ties are thought to be concurrent—one can “have” many friends at once, for instance—but their concrete enactment is largely serial and episodic, guided by priorities that steer a person from one encounter to the next. Further, dyadic encounters require that two people be simultaneously available to interact, creating the need for coordinated scheduling. Here I study the consequences of scheduling for network diffusion, using a computer simulation that interposes a scheduling process between a pre-existing network and instances of contagion. The pace and extent of diffusion are shown to depend upon the interaction of network topology, contagion rule (on first-contact versus at some threshold), and whether actors try to remedy past scheduling imperfections. Scheduling turns central actors into diffusion bottlenecks, but can also trigger early adoption by giving actors false readings on the status of their network alters. The implications of scheduling extend beyond diffusion, to other outcomes such as decision-making, as well as to network evolution.

Encounters with Levinas by Thomas Trezise (review)

1120 Reviews whereas the materialists of Documents insist on art-as-process. Adamowicz addresses Aragon's fractured narrative of collage (1923-75), exposing the ideological reading that led him to condemn Ernst's collages as frivolous, and to vaunt John Heartfield's satirical photomontages fortheir collectivist political freight.Adamowicz's critique of the erasure of collage in Aragon's slavish socio-realist writings of 1935-60 opens the way for a corrective engagement with Ernst's mesmerically poetic assault on establishment values. The study concludes with a consideration of the post-war struggle to reaffirmSurrealism under pressure from abstract experimentalism. As Breton's voice falters, a new generation deploys esoteric discourse to chart the processes of lyrical abstraction in painting: in this respect the metaphoric texts of the 1950s reprise the rhetorical strategies of the 1930s. This admirably paced study, combining close read? ing and lucid synthesis, offersan incisive examination of textual figurations that lose sight?product ively,provocatively?ofthe art works that were their catalyst. University of Wales Swansea Susan Harrow Encounters with Levinas. Ed. by Thomas Trezise. (Yale French Studies, 104) Lon? don: Yale University Press. 2004. 146 pp. ?15. ISBN 0-300-10216-x. In the useful but tantalizingly short 'Editor's Preface' to this collection of essays Thomas Trezise ascribes Levinas's now uncontested status and influence to the fact that the ethical relation to the other raises more questions than it answers. Trezise goes on to outline some of these questions (p. 2). Does Levinas's philosophical dis? course essentialize the very other whose singularity he wishes to champion? Might not discourses other than philosophy be more appropriate to the preservation of alterity ? How can the purely dyadic encounter of self and other be reconciled with issues such as justice and politics? And might not Levinas's perceived originality derive at least in part from the work of other thinkers, or from long-standing religious, philosophical, or cultural traditions? Rather than offering direct or comprehensive responses to these pertinent questions, the following essays are conceived as a series of encounters which explore some of the intellectual contexts and philosophical resonance of Levinas's work. Interesting and accomplished essays analyse Levinas's defence of subjectivity and trace its Cartesian roots (Leora Batnitzky), unravel the importance of Kierkegaard and Dostoevsky in his work (Samuel Moyn and Alain Toumayan respectively), and discuss his equivocations on the image and figuration (Philippe Crignon). If there is no startling new reading of Levinas in these essays, they nevertheless offernumerous fresh insights into aspects of his writing which have been misunderstood or neglected. Of the remaining essays, Paul Ricoeur's discussion of Otherwise than Being or Beyond Essence is already published in French, though it was certainly worthwhile to make his typically courteous but probing engagement available to anglophone scholars; and Edith Wyschogrod breaks new ground by confronting Levinas's thought with recent developments in genetic theory. Most ofthe contributors are happy to correct or criticize Levinas on occasion, but easily the most overt and challenging attack comes in Luce Irigaray's essay, 'What Other are We Talking About?', which builds upon and clarifies her chapter on Levinas mAn Ethics of Sexual Difference. She vigorously distances herself from Levinas's work, accusing him of understanding subjectivity in exclusively masculine terms and thereby silently appropriating the feminine other despite his desire to avoid fusion or pos? session. Irigaray's reading may be limited by the fact that it is based here primarily on the lectures from the 1940s published as Time and the Other, rather than taking account of Levinas's later self-revisions in, for example, Otherwise than Being or Be? yond Essence. Even so, her lively, provocative engagement is at least as much in the MLRy 100.4, 2005 1121 spirit of Levinasian encounter as the more respectful excavations of Levinas's thought and contexts, and it is to be regretted that Levinas was unwilling to respond in kind during his lifetime. In summary, this is a varied collection of essays, all of which make valuable contributions to the now massive body of secondary material on Levinas. Royal Holloway, University of London Colin Davis Andrei Makine: la rencontrede I'Est et...

Behavioural mechanisms of conflict avoidance among shrews

Stable co-existence of similar species should be facilitated by mechanisms impairing, besides exploitative, interference competition. We investigated avoidance of intra- and interspecific conflicts in a four-species community of shrews [Sorex minutus Linnaeus, 1766,S. araneus Linnaeus, 1758,Neomys anomalus Cabrera, 1907, andN. fodiens (Pennant, 1771)], using the method of dyadic encounters in a neutral arena. We tested whether the use of passive (habituation, reduction of mobility, increase of inter-individual distance, and stillness) and active (‘to-and-fro’ and ‘keeping distance’ behaviours) forms of conflict avoidance depends on species, size or domination rank. The duration of conflicts was positively correlated with mobility and negatively with inter-individual distance, whereas it was unrelated to time of stillness and the active forms. The repertoire of conflict avoidance mechanisms was not species-specific and the display of these mechanisms depended rather on the size and domination rank of animals participating in a given interaction. In contrast to rodents, shrews did not avoid conflicts by the most passive forms: freeze and stillness reactions. All other forms were used with a higher or lower efficiency by all species. However, consistent with our predictions, large shrews (asN. fodiens) used mainly the passive mechanisms of conflicts avoidance (‘wait-and-see’ strategy), whereas small shrews (asS. minutus) invest proportionally more time in active forms (‘escape’ strategy).

Role of cuticular hydrocarbons in the chemical recognition between ant species in the Pachycondyla villosa species complex

Cuticular hydrocarbons (HCs) play important roles in insect communication but few studies clearly demonstrate the direct link between HCs and nestmate recognition. Therefore, cuticular lipids were extracted from ants, their HC and non-HC fractions as well as the three principal classes of HCs ( n-alkanes, branched alkanes and alkenes) were purified and tested using an immobilizing “joust” device which allowed quantification of early pairwise behavioural responses, mandibular opening and antennal retraction, without occurrence of subsequent damages as in classic dyadic encounters. Chemical recognition of ants was studied at three levels of interactions (intra-colonial, intra-specific and inter-specific). Three closely related species already chemically characterized were used: Pachycondyla villosa (Pv), P. inversa (Pi) and P. subversa (Ps). Each species had its own behavioural responses. Moreover, responses of Pi and Ps towards Pv were significantly longer, than they were between themselves whereas Pv ants were equally aggressive towards Pi and Ps. These differences are in agreement with the results of the cluster analysis of the cuticular HCs profiles that place Pi closer to Ps. In support of the idea that components of cuticular lipids profiles are important for recognition, we found that only the HC fraction and its branched subfraction elicited a behavioural response of Ps workers. It is suggested that internally branched methyl- and dimethylalkanes are involved in recognition behaviour.

The politics of Nice

Previous discussions of politeness have focused on its function in dyadic encounters. But this basically private and individual set of strategies has uses in public and group contexts, in the behavior of persons in the public eye and the interpretation of the utterances of these figures. Americans increasingly expect their politicians, especially presidents, to be Nice (i. e., behave according to the principles of politeness, especially positive politeness). Two reasons are suggested for this novelty: the obscuring of the line between public and private, in favor of the latter, over the last 50 years; and the increasing presence of women, historically restricted to private discourse, as participants in United States public activity.

Assessment of mate preference in the house mouse with reference to investigations on assortative mating

This study analysed patterns of mate choice based on different types of laboratory test, and points out the advantages of combined methods to assess mate preference. We compared dyadic encounters and two-way choice tests involving a pair of mice or their urinary signature. Preference was assessed in males and females of the two European subspecies of the house mouse Mus musculus that share a secondary hybrid zone. A preference was deduced from directional choice or behavioural discrimination in favour of a mouse. Our results show discrepancies between the outcomes of the different types of test, which we discuss in terms of the quality of the stimuli involved, and of physical access to the information carried by those stimuli. Despite variation, our results indicate that M. m. domesticus did not show a preference, but could discriminate between stimuli of the two subspecies and tended to direct sexual behaviour assortatively. In contrast, both male and female M. m. musculus showed positive discrimination and preference for potential mates and signals carried by their own subspecies. Additionally, our results confirm that subspecies informative signals are present in mouse urine and suggest that they may be molecules of low volatility, necessitating contact for preference to be displayed.

The Smell of Success and Failure: the Role of Intrinsic and Extrinsic Chemical Signals on the Social Behavior of Crayfish

Animals commonly modify their behavior in the presence of a conspecific or in response to signals. This is particularly true in the context of aggressive exchanges, which animals use to form networks of social relationships and to communicate social status associated with those relationships. Although hierarchical structures are a widespread phenomenon that has been studied extensively, the dynamic communication processes, specifically chemical communication in this review, is relatively overlooked. In particular, it is the exchange of information during agonistic interactions that mediates hierarchies and/or alters the outcomes of agonistic interactions. Given the theoretical appeal of these interactions, and the evolutionary importance and taxonomic diversity associated with social hierarchies, it is not surprising that the sensory mechanisms involved in the formation and maintenance of hierarchical structures have received recent attention. In crayfish, dominance is thought to be largely determined by physical superiority, where encounters are largely dyadic and fighting behavior is highly stereotyped. However, recent evidence has shown that the outcome of dyadic encounters are dependent upon a number of factors other than physical size, that include the exchange of chemical information during encounters, previous social history, and the intrinsic neurochemical state of opponents. We have attempted to provide a comprehensive analysis of the extrinsic chemical processes (previous history, sensory communication, etc.) and intrinsic chemical processes (neurochemical state) that produce and maintain dominance relations and social hierarchies in crayfish. We hope that this review will bring together a global picture of the processes that determine a crayfish's social standing and how intrinsic and extrinsic chemicals have substantial effects on aggressive states and agonistic bouts.

Physician–elderly patient–companion communication and roles of companions in Japanese geriatric encounters

Although the triadic encounter of physician, patient, and an accompanying family member is a common phenomenon in geriatrics, previous research on the communication in medical encounters has primarily focused on dyadic interactions between physician and patient. This study aimed to explore the triadic communication and communication roles of patient companions in Japanese geriatric encounters. Among elderly patients aged 65 or over who were under continuous care of nine attending physicians at a university affiliated geriatric clinic in Tokyo, 63 accompanied patients and 82 unaccompanied patients were included for this study. The consultation was audiotape recorded and analyzed using the Roter Interaction Analysis System (RIAS) with additional categories developed to code aspects of companion communication. In dyadic encounters, the average proportions of physician's talk and patient's talk were 54% and 46%, respectively, while in triadic encounters the average talk proportions of physician, patient, and companion were 49%, 29%, and 22%. Companions made a significant contribution to the communication during the visit by providing information and asking the physician questions, as well as facilitating patient's talk. The companion's communication may influence not only the patient's but also the physician's communication. The patient's expectation of the companion's role during the visit and the companion's intention regarding their role were generally related to one another, and had positive associations with the companion's actual behavior during the visit. Nevertheless, companions often anticipated playing a more direct communication role during the visit, including the provision of information and asking of questions, than patients expected of them. Further investigation is needed to explore the communication dynamics in triads and dyads, and its relation to patient outcomes.