Effects Of Kinship Research Articles

Phenomenological Aspects of Hypnotic Interactions: The Effect of Kinship

This study analyzes the relationship of various measures of hypnosis as a function of kinship. Subjects with varying degrees of kinship (mono- and dizygotic twins, siblings, and parent–child pairs) participated. The Stanford Hypnotic Susceptibility Scale, Form A (SHSS:A), as well as other measures—including the Dyadic Interactional Harmony (DIH) and the Phenomenology of Consciousness Inventory (PCI)—were used with both subjects and hypnosis practitioners. Findings indicated that the phenomenological experience of hypnosis is not determined genetically. The subjects apparently evaluated the session as related to the degree of kinship. MZ twins—on the basis of reactive interactional pattern—evaluate the hypnotic interaction similarly. This was not true for SHSS:A scores or the phenomenological aspects of the state (PCI). These findings were interpreted within the sociopsychobiological model of hypnosis.

Dominance, not kinship, determines individual position within the communal roosts of a cooperatively breeding bird

Kin selection has played an important role in the evolution and maintenance of cooperative breeding behaviour in many bird species. However, although relatedness has been shown to affect the investment decisions of helpers in such systems, less is known about the role that kin discrimination plays in other contexts, such as communal roosting. Individuals that roost communally benefit from reduced overnight heat loss, but the exact benefit derived depends on an individual's position in the roost which in turn is likely to be influenced by its position in its flock's dominance hierarchy. We studied the effects of kinship and other factors (sex, age, body size and flock sex ratio) on an individual's roosting position and dominance status in captive flocks of cooperatively breeding long-tailed tits Aegithalos caudatus. We found that overall, kinship had little influence on either variable tested; kinship had no effect on a bird's position in its flock's dominance hierarchy and the effect of kinship on roosting position was dependent on the bird's size. Males were generally dominant over females and birds were more likely to occupy preferred roosting positions if they were male, old and of high status. In this context, the effect of kinship on social interactions appears to be less important than the effects of other factors, possibly due to the complex kin structure of winter flocks compared to breeding groups.

Vibrato rate variability in three professional singing styles: Opera, rock, and Brazilian country

Vibrato is one of the most expressive aesthetic characteristics of singing voice. Indicative of good voice quality is typical of lyrical singing but it is also found in others styles of popular music. Acoustically, vibrato is defined as a long-term periodic modulation of the fundamental frequency. It occurs as a result of the laryngeal muscular system and is comprised of three main parameters: rate, extent, and amplitude variation. The main controversy refers to the physiological mechanism of vibrato production, specifically concerning its neurological conscious control, as well as the intra-subject variability of its acoustic parameters. In this study, we compare the characteristics related to vibrato rate (VR), assessing 423 emissions, from recorded samples, produced by 15 professional singers, publicly and artistically acclaimed in occidental culture, to represent three music styles: opera, rock and Brazilian country (sertanejo). We analyzed the samples through GRAM 5.01 and found that the VR was kept constant intra-subject, independently of the singing style. The mean values for the VR for opera and Brazilian country singers were higher than for rock singers. Effects of vocal training, kinship and aging on the vibrato rate, as well as technical skills to control it are objects of our future studies.

Chimpanzees share food for many reasons: the role of kinship, reciprocity, social bonds and harassment on food transfers

There is currently great interest in the phylogenetic origins of altruistic behaviour within the primate order. Considerable attention has been focused on chimpanzees, Pan troglodytes, because they are our closest living relatives and participate in a wide range of collective activities, including hunting and food sharing. Food sharing is of particular importance because it plays a critical role in the human foraging niche, but food sharing among adults is rare in nonhuman primates. Some research suggests that chimpanzees selectively share meat with reciprocating partners and allies, while other work indicates that chimpanzees primarily share to reduce harassment from other group members (tolerated theft). We examined the effects of kinship, relationship quality, reciprocity and the intensity of solicitations on the pattern of food transfers in six captive groups of chimpanzees. We observed events that occurred after the chimpanzees were provisioned with large frozen juice disks. These disks share some properties with prey carcasses: they are a valued, but limited, resource; they take a considerable period of time to consume; they can be monopolized by one individual, but bits can be broken off and transferred to others. Our analyses suggest that food transfers serve multiple functions for chimpanzees. Individuals may use food transfers to enhance the welfare of closely related group members, strengthen social relationships with favoured partners and reduce the costs of persistent solicitations.

Kin Competition as a Major Driving Force for Invasions

Current theory explains accelerating invasions with increased levels of dispersal as being caused by "spatial selection." Here we argue that another selective force, strong kin competition resulting from high relatedness due to subsequent founder effects at the expanding margin, is of at least comparable importance for dispersal evolution during invasions. We test this hypothesis with individual-based simulations of a spatially structured population invading empty space. To quantify the relative contribution of kin competition to dispersal evolution, we contrast two scenarios, one including kin effects and one excluding them without influencing spatial selection. We find that kin competition is a major determinant for dispersal evolution at invasion fronts, especially under environmental conditions that favor a pronounced kin structure (i.e., small patches, low environmental stochasticity, and high patch isolation). We demonstrate the importance of kin competition and thus biotic influences on dispersal evolution during invasions.

Bonobos respond to distress in others: consolation across the age spectrum.

How animals respond to conflict provides key insights into the evolution of socio-cognitive and emotional capacities. Evidence from apes has shown that, after social conflicts, bystanders approach victims of aggression to offer stress-alleviating contact behavior, a phenomenon known as consolation. This other-orientated behavior depends on sensitivity to the other's emotional state, whereby the consoler acts to ameliorate the other's situation. We examined post-conflict interactions in bonobos (Pan paniscus) to identify the determinants of consolation and reconciliation. Thirty-six semi-free bonobos of all ages were observed at the Lola ya Bonobo Sanctuary, DR Congo, using standardized Post-conflict/Matched Control methods. Across age and sex classes, bonobos consoled victims and reconciled after conflicts using a suite of affiliative and socio-sexual behaviors including embracing, touching, and mounting. Juveniles were more likely to console than adults, challenging the assumption that comfort-giving rests on advanced cognitive mechanisms that emerge only with age. Mother-reared individuals were more likely to console than orphans, highlighting the role of rearing in emotional development. Consistent with previous studies, bystanders were more likely to console relatives or closely bonded partners. Effects of kinship, affiliation and rearing were similarly indicated in patterns of reconciliation. Nearby bystanders were significantly more likely to contact victims than more distal ones, and consolation was more likely in non-food contexts than during feeding. The results did not provide convincing evidence that bystander contacts served for self-protection or as substitutes for reconciliation. Overall, results indicate that a suite of social, developmental and contextual factors underlie consolation and reconciliation in bonobos and that a sensitivity to the emotions of others and the ability to provide appropriate consolatory behaviors emerges early in development.

Concurrent effects of familiarity and kinship on social affiliations in convict cichlid (Amatitlania siquia) young

The cues associated with social familiarity and genetic relatedness and how they interact to influence the formation of social associations among individuals, and thus group composition and dynamics, is poorly understood. Here, we investigated the concurrent effects of social familiarity and kinship on social affiliations in free-swimming convict cichlid fish young or ‘fry’ (Amatitlania siquia) by pitting the cues of social familiarity and kinship against each other in a four-way choice apparatus. Individual focal fish were given a simultaneous choice to associate (‘shoal’) with conspecifics that were either socially familiar and kin (full sibs), socially unfamiliar and kin, socially familiar and not kin, or socially unfamiliar and not kin. Stimulus shoal preference differed depending on the body length of the focal fish; smaller fry exhibited no preference, whereas larger (more mobile) fry significantly preferred to associate with familiar kin. In the convict cichlid system, where brood mixing occurs in the wild, a preference to associate with familiar kin may confer fitness benefits to individuals, especially when fry become more mobile as they grow and encounter predators more often. Our results contribute to further our understanding of the roles of familiarity and kinship in the formation of social associations in the convict cichlid in particular and in animals in general.

Kinship and Leprosy in the Contacts of Leprosy Patients: Cohort at the Souza Araújo Outpatient Clinic, Rio de Janeiro, RJ, 1987–2010

A broad variety of factors have been associated with leprosy among contacts, including socioeconomic, epidemiological, and genetic characteristics. Data from 7,174 contacts of leprosy patients from a leprosy outpatient clinic in Rio de Janeiro, Brazil, 1987–2010, were analyzed to investigate the effects of kinship, individual, and contextual factors on leprosy. Multivariate analyses were performed using a robust estimation method. In the prevalence analysis, close kinship (sibling OR = 2.75, offspring OR = 2.00, and other relatives OR = 1.70), socioeconomic factors, and the duration of exposure to the bacillus were associated to leprosy. In the incidence analysis, significant risks were found for all categories of kinship (parents RR = 10.93, spouse, boyfriend/girlfriend, and bride/groom RR = 7.53, sibling RR = 7.03, offspring RR = 5.34, and other relatives RR = 3.71). Once the treatment of the index case was initiated, other factors lost their significance, and the index case bacteriological index and BCG (Bacillus Calmette-Guérin vaccine) protection had a greater impact. Our findings suggested that both genetic susceptibility and physical exposure play an important role in the epidemiology of leprosy, but it was not possible establishing the role of genetic factor. Analyses of other factors related to the genotype of individuals, such as genetic polymorphisms, are needed.

Altruism in social networks: Evidence for a ‘kinship premium’

Why and under what conditions are individuals altruistic to family and friends in their social networks? Evolutionary psychology suggests that such behaviour is primarily the product of adaptations for kin- and reciprocal altruism, dependent on the degree of genetic relatedness and exchange of benefits, respectively. For this reason, individuals are expected to be more altruistic to family members than to friends: whereas family members can be the recipients of kin and reciprocal altruism, friends can be the recipients of reciprocal altruism only. However, there is a question about how the effect of kinship is implemented at the proximate psychological level. One possibility is that kinship contributes to some general measure of relationship quality (such as 'emotional closeness'), which in turn explains altruism. Another possibility is that the effect of kinship is independent of relationship quality. The present study tests between these two possibilities. Participants (N= 111) completed a self-report questionnaire about their willingness to be altruistic, and their emotional closeness, to 12 family members and friends at different positions in their extended social networks. As expected, altruism was greater for family than friends, and greater for more central layers of the network. Crucially, the results showed that kinship made a significant unique contribution to altruism, even when controlling for the effects of emotional closeness. Thus, participants were more altruistic towards kin than would be expected if altruism was dependent on emotional closeness alone - a phenomenon we label a 'kinship premium'. These results have implications for the ongoing debate about the extent to which kin relations and friendships are distinct kinds of social relationships, and how to measure the 'strength of ties' in social networks.

Liquidity Constraints, Kinship Networks, and the Financing of Household Investment

We look at liquidity constraints and the financing of household investment in fixed assets. We find that rural households in our sample, especially the poor, seem to face liquidity constraints. The constraints are partially mitigated by kinship networks in the village. When we further analyze gift and borrowing transaction data, we find that the kinship effect for the poor households seem to be through both gifts and borrowings while the effect for the rich households is more likely to be from gifts and not from borrowing. Using the accounting distinction between the use of a stock of cash and the cash flow, we find that rich households finance investment from previously accumulated cash, i.e. they use internally generated funds, symptomatic of constraints in a pecking order literature. As a result, we argue that although investment-cash flow sensitivity implies liquidity constraints, the reverse is not guaranteed. Finally, we also find evidence consistent with the fact that the network effect may come in both direct channels (gifts and borrowing from people within village) and indirect channels (signal of quality by being a part of the network).

Social effects on vocal ontogeny in an ungulate, the goat, Capra hircus

Vocal plasticity is the ability of an individual to modify its vocalizations according to its environment. Humans benefit from an extreme form of vocal plasticity, allowing us to produce a wide range of sounds. This capacity to modify sounds has been shown in three bird orders and in a few nonhuman mammal species, all characterized by complex vocal communication systems. In other mammals, there is no evidence for a social impact on vocal development. We investigated whether contact calls were affected by social environment and kinship during early ontogeny in goats, a highly vocal and social species. To test the influence of social environment on kid vocalizations, we compared half siblings raised in the same or different groups. The effect of kinship on calls was assessed by comparing full siblings with half siblings. Calls of half siblings were more similar when they had been raised in the same social group than in different groups, and converged with time. Full siblings had more similar calls than half siblings. The group-specific indicators in kid vocalizations show that goat call ontogeny is affected by their social environment. This suggests that vocal plasticity could be more widespread in mammals than previously believed, showing a possible early pathway in the evolution of vocal learning leading to human language.

Effect of population structure and kinship relationships on the results of association mapping tests of growth and wood quality traits in four Eucalyptuspopulations

Background In recent years, association mapping studies have been reported for growth and wood quality traits in Eucalyptus (e.g. [1]). One problem with association studies is that they can be sensitive to the presence of population structure. The presence of population structure may generate spurious associations between markers and traits and leading to an elevated false-positive rate (e.g. [2]). Statistical approaches that account for population structure include model-based clustering [3], principal component analysis, genomic control and linear mixed model approach [4]. The mixed model of Yu et al. (2006) accounts for both major population structure, assigning individuals to subpopulations (the Q matrix), and the relatedness among individuals within and between subpopulations (the kinship (K) matrix). The mixed model approach generally performs best [2,4]. As part of the Biotech MERCOSUR project (Marcucci Poltri et al. this volume) molecular and phenotypic data from four Eucalyptus populations have been obtained: three open pollinated (OP, half-sib) progeny trials of Eucalyptus grandis from Argentina (EgrAr) and Eucalyptus globulus from Uruguay (EglUy) and Argentina (EglAr) and one clonal trial of Eucalyptus grandis from Paraguay (EgrPy). These populations differ in the underlying substructure and genetic relatedness among individuals. It is thus important to investigate the effects of population structure and kinship on the results of associations between markers and growth and wood quality traits from these Eucalyptus populations.

Society, demography and genetic structure in the spotted hyena

Spotted hyenas (Crocuta crocuta) are large mammalian carnivores, but their societies, called 'clans', resemble those of such cercopithecine primates as baboons and macaques with respect to their size, hierarchical structure, and frequency of social interaction among both kin and unrelated group-mates. However, in contrast to cercopithecine primates, spotted hyenas regularly hunt antelope and compete with group-mates for access to kills, which are extremely rich food sources, but also rare and ephemeral. This unique occurrence of baboon-like sociality among top-level predators has favoured the evolution of many unusual traits in this species. We briefly review the relevant socio-ecology of spotted hyenas, document great demographic variation but little variation in social structure across the species' range, and describe the long-term fitness consequences of rank-related variation in resource access among clan-mates. We then summarize patterns of genetic relatedness within and between clans, including some from a population that had recently gone through a population bottleneck, and consider the roles of sexually dimorphic dispersal and female mate choice in the generation of these patterns. Finally, we apply social network theory under varying regimes of resource availability to analyse the effects of kinship on the stability of social relationships among members of one large hyena clan in Kenya. Although social bonds among both kin and non-kin are weakest when resource competition is most intense, hyenas sustain strong social relationships with kin year-round, despite constraints imposed by resource limitation. Our analyses suggest that selection might act on both individuals and matrilineal kin groups within clans containing multiple matrilines.

Kin presence drives philopatry and social aggregation in juvenile Desert Night Lizards (Xantusia vigilis)

Kin selection is a powerful concept in evolutionary biology that can explain both cooperative and competitive behavior. Most social behavior associated with kin selection depends on prior dispersal decisions by juveniles, which can choose to either disperse away from kin or remain at the natal site. A useful way to investigate the role of kin in social behavior is to experimentally manipulate kin environment and resolve a direct causal relationship between kin presence, dispersal strategy, and subsequent social behavior. I used a cross-fostering experiment to manipulate the relatedness of the social environment in both the laboratory and the field and test for the effects of kin on juvenile dispersal and social aggregation in the Desert Night Lizard (Xantusia vigilis). I found that kin presence actively promotes both philopatry and winter aggregation, which is consistent with the predictions of kin cooperation and suggests that kin sociality in this species is not simply a by-product of limited dispersal. In combination with kin effects known in other species, these results suggest a generality of positive associations with kin, the potential dominance of cooperative over competitive mechanisms, and the increased prominence that cooperation may have in the future theoretical study of kin selection.

The effect of kin, social network and neighbourhood support on individual well-being

This paper explores the effects of kin, social network and the neighbourhood on an individual's well-being. The material is drawn from a community-based qualitative study that explored the attitudes and experiences of African-Caribbean adolescents and their families in the north of England towards healthy lifestyles. A convenience sample of 10 African-Caribbean households units comprising 24 adolescents (12-18 years of age) and 18 adults (22-60 years of age) participated in the study with interviews conducted in their homes. The paper focuses on the adult participants' perception of the role of social support networks and neighbourhood effects on well-being. An in-depth interview schedule was used to explore participants' perceptions on barriers to health and healthy lifestyles; and factors facilitating and inhibiting good health and healthy lifestyles. Data were subjected to thematic analysis with the aid of a Qualitative Data Analysis software package. Emerging categories were discussed with participants by conducting post interview visits and at community events. Findings indicated that participants believed that being a member of a kin network enhanced one's well-being, with such networks described as capable of providing protective support for one's health and well-being. In addition, they preferred to live in neighbourhoods with a high concentration of people of the same ethnicity, despite the effects of neighbourhood deprivation such as poor housing and lack of services. However, participants believed that ethnic segregation leads to marginalisation and further deprivation. These findings suggest that there is a need to explore further the influence of social networks and neighbourhoods on the full spectrum of an individual's well-being. The study concludes by suggesting that in considering new paradigms for the promotion of well-being, health and social care practitioners need to incorporate ways to promote social support and consider relevant psychosocial and neighbourhood factors in designing models of community well-being.

Grooming reciprocity in wild male chimpanzees

Understanding cooperation between unrelated individuals remains a central problem in animal behaviour; evolutionary mechanisms are debated, and the importance of reciprocity has been questioned. Biological market theory makes specific predictions about the occurrence of reciprocity in social groups; applied to the social grooming of mammals, it predicts reciprocity in the absence of other benefits for which grooming can be exchanged. Considerable effort has been made to test this grooming trade model in nonhuman primates; such studies show mixed results, but may be confounded by kin effects. We examined patterns of reciprocity within and across bouts, and tested predictions of the grooming trade model, among wild male chimpanzees, Pan troglodytes: a system with negligible kin effects. In accord with the model’s expectations, we found that some grooming was directed by lower- to higher-ranked individuals, and that, on average, higher-ranked individuals groomed more reciprocally. We found no support, however, for a prediction that more reciprocity should occur between individuals close in rank. For most dyads, reciprocity of effort occurred through unbalanced participation in grooming bouts, but reciprocity varied considerably between dyads and only a small proportion showed strongly reciprocal grooming. Despite this, each male had at least one reciprocal grooming relationship. In bouts where both individuals groomed, effort was matched through mutual grooming, not alternating roles. Our results provide mixed support for the current grooming trade, biological market model, and suggest that it needs to incorporate risks of currency inflation and cheating for species where reciprocity can be achieved through repeated dyadic interactions. 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. Altruistic acts are behaviours that benefit the recipient at an apparent cost to the actor (Trivers 1971). The theory of reciprocal altruism holds that such acts can evolve by natural selection if the roles of actor and recipient are reciprocated such that both incur costs (albeit offset in time) and obtain net fitness benefits. Evidence for the role of this ‘direct reciprocity’ in shaping altruistic behaviour among animal species is limited, however (Clutton-Brock 2009). Originally modelled using the Prisoner’s Dilemma (Trivers 1971), increasingly sophisticated game-theoretical approaches have been developed to accommodate more realistic assumptions. In the Prisoner’s Dilemma, individuals are constrained into interacting with a particular partner, and have only a choice between cooperation or noncooperation, with the value of cooperation equal to both partners (Trivers 1971). In contrast, for animals living in social groups, choice of partners for social interactions is common (Wilkinson 1984; Noe et al. 1991; Emery 2004; Connor 2007;

How Grandparents Matter

Low birth rates in developed societies reflect women’s difficulties in combining work and motherhood. While demographic research has focused on the role of formal childcare in easing this dilemma, evolutionary theory points to the importance of kin. The cooperative breeding hypothesis states that the wider kin group has facilitated women’s reproduction during our evolutionary history. This mechanism has been demonstrated in pre-industrial societies, but there is no direct evidence of beneficial effects of kin’s support on parents’ reproduction in modern societies. Using three-generation longitudinal data anchored in a sample of grandparents aged 55 and over in 1992 in the Netherlands, we show that childcare support from grandparents increases the probability that parents have additional children in the next 8 to 10 years. Grandparental childcare provided to a nephew or niece of childless children did not significantly increase the probability that those children started a family. These results suggest that childcare support by grandparents can enhance their children’s reproductive success in modern societies and is an important factor in people’s fertility decisions, along with the availability of formal childcare.

Communication in social networks: Effects of kinship, network size, and emotional closeness

Communication is important in preventing social relationships from decaying over time. This study examined the effects of social network size, emotional closeness, and type of relationship (kinship vs. friendship) on communication patterns in the social networks of 251 women. Participants with large kin networks had longer times to last contact to both kin and friends. Participants with high levels of emotional closeness in their networks had shorter times to last contact. The effect of emotional closeness on time to last contact was greater for kin than for friends. These results demonstrate that time to last contact is closely tied to emotional closeness and suggest that the costs of maintaining kin relationships are lower than the costs of maintaining friendships.

Food-Sharing Networks in Lamalera, Indonesia

Exponential random graph modeling (ERGM) is used here to test hypotheses derived from human behavioral ecology about the adaptive nature of human food sharing. Respondents in all (n=317) households in the fishing and sea-hunting village of Lamalera, Indonesia were asked to name those households to whom they had more frequently given (and from whom they had more frequently received) food during the preceding sea-hunting season. The responses were used to construct a social network of between-household food-sharing relationships in the village. The results show that kinship, proximity, and reciprocal sharing all strongly increase the probability of giving food to a household. The effects of kinship and distance are relatively independent of each other, while reciprocity is more common among residentially and genealogically close households. The results show support for reciprocal altruism as a motivation for food sharing while kinship and distance appear to be important partner-choice criteria.

Conflicts induce affiliative interactions among bystanders in a tolerant species of macaque ( Macaca tonkeana)

Aggression is potentially disruptive for social groups. Although individuals witnessing a conflict are not directly threatened by aggressive interactions, the aftermath of aggression appears to be a period of social instability. We expected bystanders to respond to conflicts by affiliating with other group members and so reducing social tension. To test this hypothesis we collected data on two captive groups of Tonkean macaques, Macaca tonkeana. After an agonistic interaction, the behaviours of focal individuals uninvolved in the conflict were recorded over 5 min postconflict periods, for comparison with baseline periods. The results showed that bystanders were more likely to show affiliation during postconflict periods than in baselines. We found that affiliation occurred more frequently between individuals linked by friendship, whereas no significant effect of kinship appeared, which may be related to the open social relationships reported in Tonkean macaques. Females initiated affiliation sooner than males and conflicts involving physical contact were more quickly followed by affiliation between bystanders. Rates of scratching tended to decrease after the first affiliative interaction. None the less, few signs of anxiety were observed in bystanders. Our results reflect the high propensity of Tonkean macaques to appease others and stop aggression. This study demonstrates that postconflict affiliation occurs between bystanders in a species characterized by tolerant social relationships. It could be a pervasive means of social cohesion among primates.