Showing papers on "Dominance (ethology) published in 2006"

Social dominance theory and the dynamics of intergroup relations: Taking stock and looking forward

Abstract: This chapter reviews the last 15 years of research inspired by social dominance theory, a general theory of societal group-based inequality. In doing so, we sketch the broad outlines of the theory and discuss some of the controversies surrounding it, such as the “invariance hypothesis” regarding gender differences in social dominance orientation (SDO) and the effect of social context on the expression of SDO. We also discuss the central role of gender in the construction and maintenance of group-based inequality, and review some of the new research inspired by the social dominance perspective. Finally, we identify and discuss some of the most important theoretical questions posed by social dominance theory that are yet to be researched.

Implicit Bias: Scientific Foundations

Abstract: The assumption that human behavior is largely under conscious con trol has taken a theoretical battering in recent years. Although this assault in some ways resembles the previous century's Freudian revolution, there are important differences between the two. Freud's views of unconscious mechanisms were embedded in a theory that never achieved conclusive support among scientists, despite many empirical theory-testing efforts in the middle third of the twentieth century.1 Consequently, most psycholo gists have abandoned Freud's psychoanalytic theory of unconscious mental processes. Theoretical conceptions of conscious control over human behavior were strongly re-established in the last third of the twentieth century, but the dominance of such views has been crumbling during the past two dec ades. Unlike the Freudian revolution, however, the new science of

Overconfidence in wargames: experimental evidence on expectations, aggression, gender and testosterone

Abstract: Overconfidence has long been noted by historians and political scientists as a major cause of war. However, the origins of such overconfidence, and sources of variation, remain poorly understood. Mounting empirical studies now show that mentally healthy people tend to exhibit psychological biases that encourage optimism, collectively known as 'positive illusions'. Positive illusions are thought to have been adaptive in our evolutionary past because they served to cope with adversity, harden resolve, or bluff opponents. Today, however, positive illusions may contribute to costly conflicts and wars. Testosterone has been proposed as a proximate mediator of positive illusions, given its role in promoting dominance and challenge behaviour, particularly in men. To date, no studies have attempted to link overconfidence, decisions about war, gender, and testosterone. Here we report that, in experimental wargames: (i) people are overconfident about their expectations of success; (ii) those who are more overconfident are more likely to attack; (iii) overconfidence and attacks are more pronounced among males than females; and (iv) testosterone is related to expectations of success, but not within gender, so its influence on overconfidence cannot be distinguished from any other gender specific factor. Overall, these results constitute the first empirical support of recent theoretical work linking overconfidence and war.

Foraging strategies as a function of season and rank among wild female chimpanzees (Pan troglodytes)

Abstract: Among mammals, female reproduction is generally thought to be food limited, and dominance should theoretically afford high-ranking females with access to better food resources. Although the importance of dominance rank among female chimpanzees (Pan troglodytes) has been debated in the past, mounting evidence suggests that rank is very important among females (P. t. schweinfurthii) at Gombe National Park, Tanzania. In this study, we investigated the influence of season and dominance rank on female foraging strategies. We found that high-ranking females spent less time foraging and tended to have a narrower diet breadth and higher diet quality than subordinate females. In this way, subordinate female foraging strategies were consistent with how females in general adapted to periods of food scarcity. The results of this study therefore suggest that low-ranking females may face persistent ‘‘food scarcity’’ as a result of interference food competition. We also provide evidence that subordinates may forage less efficiently because they occupy lower quality habitats or avoid associating with dominant females in shared areas.

Dominance in vertebrate broods and litters.

Abstract: Drawing on the concepts and theory of dominance in adult vertebrates, this article categorizes the relationships of dominance between infant siblings, identifies the behavioral mechanisms that give rise to those relationships, and proposes a model to explain their evolution. Dominance relationships in avian broods can be classified according to the agonistic roles of dominants and subordinates as “aggression‐submission,” “aggression‐resistance,” “aggression‐aggression,” “aggression‐avoidance,” “rotating dominance,” and “flock dominance.” These relationships differ mainly in the submissiveness/pugnacity of subordinates, which is pivotal, and in the specificity/generality of the learning processes that underlie them. As in the dominance hierarchies of adult vertebrates, agonistic roles are engendered and maintained by several mechanisms, including differential fighting ability, assessment, trained winning and losing (especially in altricial species), learned individual relationships (especially in ...

Nonverbal expressions of dominance and power in human relationships

Abstract: F undamental to all social species is the negotiation and expression of dominance and power relationships. Whether it is establishing a pecking order or a marching order, proclaiming privileges or prohibitions, exercising leadership or intimidation, humans, like other mammals, have evolved intricate means of signaling in any social encounter who are “one up” or “one down,” who can “have” or “have not,” who “goes before” or “goes after.” Such signaling is a necessity for creating

The expression of social dominance following neonatal lesions of the amygdala or hippocampus in rhesus monkeys (Macaca mulatta).

Abstract: As part of ongoing studies on the neurobiology of socioemotional behavior in the nonhuman primate, the authors examined the social dominance hierarchy of juvenile macaque monkeys (Macaca mulatta) that received bilateral ibotenic acid lesions of the amygdala or the hippocampus or a sham surgical procedure at 2 weeks of age. The subjects were reared by their mothers with daily access to large social groups. Behavioral observations were conducted while monkeys were given access to a limited preferred food. This testing situation reliably elicited numerous species-typical dominance behaviors. All subjects were motivated to retrieve the food when tested individually. However, when a group of 6 monkeys was given access to only 1 container of the preferred food, the amygdala-lesioned monkeys had less frequent initial access to the food, had longer latencies to obtain the food, and demonstrated fewer species-typical aggressive behaviors. They were thus lower ranking on all indices of social dominance. The authors discuss these findings in relation to the role of the amygdala in the establishment of social rank and the regulation of aggression and fear.

Social foraging and dominance relationships: the effects of socially mediated interference

Abstract: In socially foraging animals, it is widely acknowledged that the position of an individual within the dominance hierarchy of the group has a large effect upon its foraging behaviour and energetic intake, where the intake of subordinates can be reduced through socially mediated interference. In this paper, we explore the effects of interference upon group dynamics and individual behaviour, using a spatially explicit individual-based model. Each individual follows a simple behavioural rule based upon its energetic reserves and the actions of its neighbours (where the rule is derived from game theory models). We show that dominant individuals should have larger energetic reserves than their subordinates, and the size of this difference increases when either food is scarce, the intensity of interference suffered by the subordinates increases, or the distance over which dominant individuals affect subordinates increases. Unlike previous models, the results presented in this paper about differences in reserves are not based upon prior assumptions of the effects of social hierarchy and energetic reserves upon predation risk, and emerge through nothing more than a reduction in energetic intake by the subordinates when dominants are present. Furthermore, we show that increasing interference intensity, food availability or the distance over which dominants have an effect also causes the difference in movement between ranks to increase (where subordinates move more than dominants), and the distance over which dominants have an effect changes the size of the groups that the different ranks are found in. These results are discussed in relation to previous studies of intra- and interspecific dominance hierarchies.

Rape as a Tactic of War: Social and Psychological Perspectives

Abstract: For centuries, the rape of women has been used as a tactic of war to advance one group's political, economic, social, or religious position over another. Systematic mass rape devastates individual ...

Driven to Tears or to Joy: Response Dominance and Trait-Based Predictions

Abstract: The present studies reinvigorate the construct of traitedness from a cognitive perspective. Tendencies toward habit (vs. flexibility) were assessed by examining response dominance performance within choice reaction time tasks. Consistent with the idea that response dominance reflects a tendency toward habitual modes of thought and action, three studies involving 428 undergraduates revealed that trait-outcome and test-retest correlations were higher among individuals higher in response dominance. In Studies 1 and 2, such trait-consistency effects took the form of stronger relations between extraversion and neuroticism, on one hand, and mood states and behavior, on the other. In Study 3, such tendencies took the form of higher test-retest correlations related to daily experiences of mood states, somatic symptoms, and life satisfaction. Together, the studies reveal a consistent effect of response dominance on trait-like consistency and raise some important issues for future studies of the traitedness construct.

Social Dominance and Male Breeding Success in Captive White‐Tailed Deer

Abstract: Management strategies that incorporate the social behavior of wildlife may be more efficient in achieving population objectives. Our current knowledge of white-tailed deer (Odocoileus virginianus) social behaviors may not be adequate for application to management. Using captive white-tailed deer, we investigated the long-held assumption that relatively few dominant males sire most offspring and, thus, prevent subordinates from breeding. Although this assumption influences population predictions and management strategies, empirical studies of the relationship between dominance and male breeding success in deer are lacking. We determined male dominance rank and genetic paternity through 6 breeding trials. Although dominant males sired most offspring, subordinates sired offspring in 5 of 6 trials and multiple paternity (siring of offspring by 2 males) occurred in ∼24% of compound litters. Further, male dominance ranks were not necessarily predictable or stable during the breeding season. This study indicates that the relationship between social dominance and male breeding success may be more complex than previously thought. Our findings also are consistent with recent studies of parentage in wild deer, providing additional evidence that social dominance does not necessarily equate to breeding success. Conceptual models of deer breeding behaviors should account for considerable individual heterogeneity among males in their ability to sire offspring.

Minimal relativism, dominance, and standard of living comparisons based on functionings

Abstract: This paper considers the functioning approach to the standard of living. It shows that, in evaluating standards of living, one is faced with deep-rooted tensions between the principle of weak dominance and the principle of minimal relativism, which requires some minimal respect for differences between the evaluations of different individuals and/or the differences between the norms of different communities.

Influence of Pitch Height on the Perception of Submissiveness and Threat in Musical Passages

Abstract: Bolinger, Ohala, Morton and others have established that vocal pitch height is perceived to be associated with social signals of dominance and submissiveness: higher vocal pitch is associated with submissiveness, whereas lower vocal pitch is associated with social dominance. An experiment was carried out to test this relationship in the perception of non-vocal melodies. Results show a parallel situation in music: higher-pitched melodies sound more submissive (less threatening) than lower-pitched melodies. RESEARCH by Bolinger, Ohala, Morton and others has established that vocal pitch height (F0) is perceived to be associated with social cues for dominance and submissiveness. In a wide sample of cultures, Bolinger (1964) noted that high or rising vocal pitch is associated with politeness, deference, submissiveness and lack of confidence. Bolinger also showed that conversely, low or falling vocal pitch is associated with authority, threat, aggression, and confidence. Ohala (1984) and Morton (1994) have assembled additional support for this association in ethological studies of non-human animals. Paradoxically, an earlier study by Scherer et al. (1973) seemed to suggest that high vocal pitch is associated with aggression; however, Ohala (1994) has noted that the materials studied by Scherer et al. exhibit marked descending pitch contours. That is, beginning from a high pitch may allow a more exaggerated pitch descent, corresponding to a presumed confident or aggressive assertion. This association has been demonstrated in both ecological and controlled experimental situations. Morton (1994) reviewed vocalizations for 54 species as observed by ethologists. Morton noted that three features appear to be important in aggressive/passive signaling. First, low-pitched sounds are generally associated with aggressive signaling, whereas high-pitched sounds are generally associated with friendly, appeasing, or fearful signals. Second, falling pitch contours are generally associated with aggression, while rising pitches are associated with friendly, appeasing, or fearful signals. Finally, Morton drew attention to the (periodic) tone versus (aperiodic) noise distinction. In general, hostile signals are described as raspy, growling, buzzing, or snarling. Such sounds are often characterized as "harsh." By contrast, friendly or appeasing signals are typically described as whimpers, whines, squeaks, squeals, screeches, or chirps. In general, those tones which evoke the clearest pitch sensations are associated with friendly and appeasing signals, whereas unpitched noises or less clearly pitched tones are associated with aggression. To Morton's three factors we may add a fourth - loudness. Loudness seems to be interpretable in two ways. First, loudness may be associated with the urgency of the signal. That is, a loud vocalization may indicate a strong desire to communicate or to communicate clearly. In addition, increased loudness is also likely correlated with hostility or aggression; the acoustic power might suggest the physical power of the individual or signal the individual's willingness to engage in physical confrontation.

The logic of Islamic practice: a religious conflict in Central Asia1

Abstract: In the afterword to the 1995 edition of Orientalism and in the preface to the 2003 edition Edward Said expressed his regret at the continuing dominance of the ideological fictions of the ‘West’, th...

Dominance detection in meetings using easily obtainable features

Abstract: We show that, using a Support Vector Machine classifier, it is possible to determine with a 75% success rate who dominated a particular meeting on the basis of a few basic features. We discuss the corpus we have used, the way we had people judge dominance and the features that were used.

Describing the organization of dominance relationships by dominance-directed tree method.

Abstract: Methods to describe dominance hierarchies are a key tool in primatology studies. Most current methods are appropriate for analyzing linear and near-linear hierarchies; however, more complex structures are common in primate groups. We propose a method termed "dominance-directed tree." This method is based on graph theory and set theory to analyze dominance relationships in social groups. The method constructs a transitive matrix by imposing transitivity to the dominance matrix and produces a graphical representation of the dominance relationships, which allows an easy visualization of the hierarchical position of the individuals, or subsets of individuals. The method is also able to detect partial and complete hierarchies, and to describe situations in which hierarchical and nonhierarchical principles operate. To illustrate the method, we apply a dominance tree analysis to artificial data and empirical data from a group of Cebus apella.

Graduate versus non-graduate entrepreneurs in urban Malaysia: some insights into entrepreneurial personality, company and family background differences

Abstract: The study attempts to explore the relationship of the level of education (graduate and non-graduate) with personality, family background and company background of entrepreneurs in urban Malaysia. Three demographic variables and one business characteristics variable were found to be significantly different between graduate and non-graduate entrepreneurs. Overall, in terms of entrepreneurial personality characteristics, both graduate and non-graduate entrepreneurs scored high with respect to the Pursuit of Excellence; moderately high on Work Ethics; moderate on Dominance, Mastery and Internal Attributing and moderately low on Powerful Others and Chance Attributing dimensions. The Chance Attributing dimension was found to be statistically significant in differentiating the two groups, whereas 'pursuit of excellence' and 'dominance' dimensions were marginally significant. The implications of the study are also discussed along with some recommendations.

Language Dominance and PerformanceOutcomes in Bilingual Pronunciation

Abstract: A significant body of experimental and naturalistic studies has demonstrated that bilingual speakers of Romance language–English pairings are capable of creating separate phonetic categories for the production of voiceless stops, measured as voiced onset time (VOT), across their languages (Caramazza, Yeni-Komshian, Zurif & Carbone, 1973; Flege & Eefting, 1987: Major, 1992, interalia). However, bilinguals equally tend to show altered, either converged or exaggerated VOT values in one or both of their languages relative to the those of monolingual speakers. Sancier and Fowler’s (1997) case study of a Portuguese-English bilingual suggests that a bilingual’s VOT values are not fixed; rather they tend to drift according to the ambient speech environment. They label the phenomenon observed in their study as “gestural drift” because the gradient changes to VOT are observed in both the speaker’s L1 (Portuguese) and L2 (English). Gestural drift is consistent with Grosjean’s (2001) notion of “language mode” and with Escudero and Boersma’s (2002) “perceptual mode.” Such research contends that bilinguals’ language use is malleable in that they may behave differently according to which language they are producing or perceiving at a given time. The focus of the present study is to examine the effect of language mode on VOT production in real time via the use of a linguistic code-switching task. As code-switching arguably requires bilinguals to activate both languages simultaneously, it is expected that speakers should manifest VOT values in code-switched tasks that differ significantly from their productions in monolingual modes. At issue is the extent to which each of a bilingual’s component languages is affected by code-switching. Gestural drift implies that they should be equally vulnerable to inter-linguistic influence. But if phonetic categories are established early in childhood then we would expect that bilinguals’ L1 categories should be resistant to incursions from the L2 but not vice-versa.

Sexual strategies theory and Internet personal advertisements.

Abstract: Sexual Strategies Theory supposes that certain characteristics—namely, physical attractiveness in women and dominance and the ability to provide material resources in men—are highly desirable to po...

Effects of Previous Experience on the Agonistic Behaviour of Male Crickets, Gryllus bimaculatus

Abstract: Male solitary animals frequently enter aggressive interactions with conspecific individuals to protect their territory or to gain access to females. After an agonistic encounter, the loser (subordinate individual) changes its behaviour from aggression to avoidance. We investigated agonistic interactions between pairs of male crickets to understand how dominance is established and maintained. Two naive males readily entered into agonistic interactions. Fights escalated in a stereotyped manner and were concluded with the establishment of dominance. If individuals were isolated after the first encounter and placed together 15 minutes later, subordinate crickets tended to avoid any further contact with the former dominant opponent. Moreover, subordinate males also avoided unfamiliar dominant and naive opponents. They displayed aggressive behaviour only towards unfamiliar subordinate opponents. This suggests that the subordinate male change their behaviour depending on the dominance status of the opponent. Dominant crickets, in contrast, displayed aggressive behaviour towards familiar as well as unfamiliar opponents. If the interval between the first and second encounter was longer than 30 minutes, the former subordinate male showed aggressive behaviour again. However, if the subordinate cricket was paired with the same opponent three consecutive times within 45 minutes, it avoided the former dominant opponent for up to 6 hours following the third encounter. Our results suggest that the maintenance of dominance in male crickets depends largely on the behavioural change of subordinate individuals. Possible mechanisms to maintain dominance are discussed.

Captive female gorilla agonistic relationships with clumped defendable food resources

Abstract: Minimal feeding competition among female mountain gorillas (Gorilla gorilla beringei) has resulted in egalitarian social relationships with poorly defined agonistic dominance hierarchies. Thus, gorillas are generally viewed as non-competitive egalitarian folivores that have had little need to develop effective competitive strategies to access food resources. However, this generalization is inconsistent with more recent research indicating that most gorillas are frugivorous, feeding on patchily distributed food resources. The current study at Howletts Wild Animal Park, Kent, England, explores the effects of clumped and defendable foods on female gorilla agonistic relationships among three groups of western lowland gorillas (G. g. gorilla), conditions that are predicted to lead to well-differentiated agonistic dominance hierarchies among female primates. The Howletts gorillas foraged all day on low-energy/-nutrient, high-fiber foods widely distributed around their enclosure by the keepers. However, they also had periodic access to high-energy foods (e.g., nuts, raisins, strawberries, etc.) that the keepers would spread in a clumped and defendable patch. Frequencies of agonistic and submissive behaviors between females and proximity data were gathered. High-status females were found to monopolize the food patch and kept the low-status females at bay with cough-grunt threat vocalizations or by chasing them away. Agonistic interactions were initiated mostly by females of high status; these were directed towards females of low status and were generally not reciprocal. In addition, females of low status engaged in submissive behaviors the most often, which they directed primarily at females of high status, especially in response to aggression by the latter. Agonistic interactions between high- and low-status females had decided outcomes more often than not, with low-status females the losers. Competition over highly desirable foods distributed in defendable clumps at Howletts appears to have led to well-defined dominance relationships among these female gorillas.

Epilepsy: disease and model to study human brain function.

Abstract: Introduction Epilepsy is one of the most common neurological disorders, affecting almost 1% of the population. In many patients, a focal onset of seizure activity within the temporal lobe can be detected. Neurophysiological recordings, high-resolution brain imaging and neuropathological analysis of surgical brain specimens identify the hippocampus as the major target structure being affected in patients with temporal lobe epilepsy (TLE). Moreover, removal of this structure during epilepsy surgery is effective in controlling seizures in these patients. Since temporal lobe structures such as the hippocampus are also critically involved in learning and memory formation, clinical and neuropsychological investigations of epilepsy patients open new avenues to study mechanisms of higher order brain functions in human, such as declarative memory processes. Quantitative measurements of neuropsychological deficits in patients with TLE help to generate new concepts on how the information is stored and recalled in the human brain. For instance, our studies have revealed that the hippocampus of the dominant hemisphere contributes significantly to novelty detection during verbal memory formation, an important decisive process linked to long-term memory storage. In addition to neuropsychological, in vivo neurophysiological and imaging studies, the availability of living hippocampal brain tissue following epilepsy surgery allows to analyze cellular and molecular mechanisms of activity-dependent plasticity, ie, long term potentiation. With further advances in clinical and basic neurosciences and high resolution imaging, our understanding of how the human brain is functionally organized and sensory information is processed will continuously increase. Thus, epilepsy constitutes a unique model disease to systematically study human brain function on different levels. Epilepsy and the Functional Anatomy of the Human Brain In 1954 Wilder Penfield and Herbert Jasper published their milestone textbook Epilepsy and the Functional Anatomy of the Human Brain (14). The unique data presented in this publication were based on electrophysiological recordings obtained during epilepsy surgery and local anesthesia of the patient. Until that time, brain stimulation experiments had been carried out only in experimental animals, and non-invasive techniques were not available to characterize eloquent brain regions in humans, ie, motor or speech areas. The result of many hundreds of patients analyzed during epilepsy surgery at the Montreal Institute of Neurology established a coherent functional brain map of the human brain, which is still valid for most instances, replacing and extending previous brain maps derived from postmortem analysis of traumatic brain injury, tumors or stroke. It was the pioneering attitude of Penfield and Jasper to recognize that epilepsy surgery bears remarkable promise to study high order human brain function in conscious human. Today the experimental opportunities associated with epilepsy surgery have extended substantially (2, 8). Experimental analysis is no longer confined to the short period during which surgery and local anesthesia takes place. In many patients, intracerebral electrodes are implanted in order to identify the epileptic focus and/or eloquent brain areas that could be potentially compromised by a surgical intervention (Figure 1). For identification of the epileptic focus, recording spontaneous seizures is essential. During the time period of hospitalization during which patients wait for spontaneous seizures (7-20 days), bioelectrical parameters of specific brain areas, even in the depth of the mesial temporal lobe, and their association with the patient’s neuropsychological ability and behavior can be quantitatively measured. The application of modern neurobiological techniques to human brain specimens from the epileptogenic area resected during epilepsy surgery represent yet another major research avenue (3). Neuropathological examination including immunohistochemical and ultrastructural techniques allow to precisely classify specific disorders underlying focal epileptogenesis (see Blümcke et al, Crino et al, this issue). In addition, living SYMPOSIUM: Pathogenesis and Pathophysiology of Focal Epilepsies

The importance of social relationships in horses

Abstract: Feral horses are social animals, which have to rely on survival strategies centered on the formation of cohesive social bonds within their bands. Many problems in the husbandry of social animals such as horses, are due to the fact that the limits of their adaptive abilities are exceeded. Evidence suggests that the fundamental social characteristics of domestic horses have remained relatively unchanged. The social structure, social strategies and social interactions were investigated (3 non-consecutive years, 24 hr per day for several weeks) in long term established groups of domestic horses (mares and geldings of all ages) and a few small introduced groups, kept in (semi)natural environments. The general aim was to investigate the social needs of domestic horses. The social life of domestic horses was characterised by long lasting bonds with preferred partners which were established and maintained by allogrooming, play, proximity and dominance behaviours. Bonding partners were mainly found within the same sex-age group, but adult geldings also bonded with sub-adult mares and geldings. Adult mares were clustered in a group, while the other animals formed a second group. Among the adult mares, subgroups according to reproductive state were formed. Individuals regulated their social network by interfering with interactions between other members of the herd, which in itself is complex. An intervention is a behavioural action of one animal that actively interferes with an ongoing interaction between a dyad with the apparent aim of altering that interaction. This was verified by post-hoc analyses of disturbed and undisturbed interactions. Interventions in allogrooming or play were performed significantly more often when at least one member of the initial dyad was a preferred partner of, or familiar to (within the small introduced bands) the intervener. The stronger the preferred association in allogrooming between the intervener and member(s) of the initial dyad, the higher the probability the intervener would displace one initial member and continue allogrooming with the other. Just five behaviours were extracted which reliably reflected the dominance relations among horses. Aggression with the hind quarters was used both offensively and defensively and therefore not suitable as a reliable parameter. Individual dominance relationships were related to social experience. The implications of these findings for horse husbandry were assessed. It is argued that the execution of affiliative behaviours may be rewarding in itself, and therefore always will be a highly motivated behaviour. It is shown that social positive physical interactions (allogrooming, play) with other horses is an ethological need and therefore indispensable in modern husbandry systems. Ethological needs are so important for the animal that husbandry systems that lack the possibilities to execute such behaviours will cause chronic stress. It is concluded that all horses need physical social contact, and that horses, which lack appropriate social learning experiences during ontogeny, may be hampered in their social functioning later in life. Solutions for problems, including dominance problems, in individual social housing and group housing are presented.