Host Sibling Research Articles

When parents die: Bereavement, decision-making and achieving adult personhood in rural Togo

Death has received considerable attention in the social sciences when it comes to rites of passage, for example, funerals, cremations, vigils, or memorial services. As elders pass away, the generations shift, and former youths become elders themselves. This paper presents the case of my host father, a local notable in northern Togo, who died in 2018 and was honoured by an extensive mourning ritual the following year. Drawing on intense and active participant observation, I show the challenges my host sibling group faced in achieving social adulthood. Through daily decision-making processes, this group of grown sons and daughters shaped, manipulated and reorganised the configuration of rituals, addressing issues of succession, conflicts between animist and Christian rites, and whether to classify cattle gifts as ancestral honours or delayed bridal gifts. Making such decisions at the end of elders’ lives is a crucial process for the rising generation to achieve adult social status.

Prophages in Salmonella enterica: a driving force in reshaping the genome and physiology of their bacterial host?

SummaryThanks to the exponentially increasing number of publicly available bacterial genome sequences, one can now estimate the important contribution of integrated viral sequences to the diversity of bacterial genomes. Indeed, temperate bacteriophages are able to stably integrate the genome of their host through site‐specific recombination and transmit vertically to the host siblings. Lysogenic conversion has been long acknowledged to provide additional functions to the host, and particularly to bacterial pathogen genomes where prophages contribute important virulence factors. This review aims particularly at highlighting the current knowledge and questions about lysogeny in Salmonella genomes where functional prophages are abundant, and where genetic interactions between host and prophages are of particular importance for human health considerations.

Child Fostering in Senegal

Child fostering is a practice widespread in Sub-Saharan Africa whereby children are temporarily sent to live with a host family. Using a rich household survey conducted in Senegal in 2006-7, the paper aims at describing the selection into fostering of both households and children and at examining the impact of fostering on the wellbeing of children (host, foster- and siblings left behind) measured through their school enrollment, labour and domestic work. Results suggest a wide heterogeneity among foster children, inducing differences in their wellbeing. The main sources of such heterogeneity come from the child’s gender and his duration of stay in the host household. Whether the fostering has been formally arranged between parents also seems to matter. Results are reassuring regarding the well-being of fostered children relative to their host siblings, even if they might not fare as well as children not involved in fostering. On average, education and labour outcomes of foster children are not different from those of their host siblings. In particular, results do not support the idea that fostered girls might be overloaded with domestic tasks: they do not seem to spend more time at it than their host sisters.

Apparent vector-mediated parent-to-offspring transmission in an avian malaria-like parasite.

Parasite transmission strategies strongly impact host-parasite co-evolution and virulence. However, studies of vector-borne parasites such as avian malaria have neglected the potential effects of host relatedness on the exchange of parasites. To test whether extended parental care in the presence of vectors increases the probability of transmission from parents to offspring, we used high-throughput sequencing to develop microsatellites for malaria-like Leucocytozoon parasites of a wild raptor population. We show that host siblings carry genetically more similar parasites than unrelated chicks both within and across years. Moreover, chicks of mothers of the same plumage morph carried more similar parasites than nestlings whose mothers were of different morphs, consistent with matrilineal transmission of morph-specific parasite strains. Ours is the first evidence of an association between host relatedness and parasite genetic similarity, consistent with vector-mediated parent-to-offspring transmission. The conditions for such 'quasi-vertical' transmission may be common and could suppress the evolution of pathogen virulence.

Discrimination of the Social ParasiteEctatomma parasiticumby Its Host Sibling Species (E. tuberculatum)

Among social parasites, workerless inquilines entirely depend on their host for survival and reproduction. They are usually close phylogenetic relatives of their host, which raises important questions about their evolutionary history and mechanisms of speciation at play. Here we present new findings onEctatomma parasiticum, the only inquiline ant described in the Ectatomminae subfamily. Field data confirmed its rarity and local distribution in a facultative polygynous population ofE. tuberculatumin Mexico. Genetic analyses demonstrated that the parasite is a sibling species of its host, from which it may have diverged recently. Polygyny is suggested to have favored the evolution of social parasite by sympatric speciation. Nevertheless, host workers from this population were able to discriminate parasites from their conspecifics. They treated the parasitic queens either as individuals of interest or as intruders, depending on their colonial origin, probably because of the peculiar chemical profile of the parasites and/or their reproductive status. We suggest thatE. parasiticumcould have conserved from its host sibling species the queen-specific substances that produce attracting and settling effect on workers, which, in return, would increase the probability to be detected. This hypothesis could explain the imperfect social integration of the parasite into host colonies.

DEL AF FAMILIEN: Penge og gavegivning i danske udvekslingsfamilier

This article deals with the financial aspect of kinship and is based on field data collected
 in Denmark among ‘exchange families’ consisting of Danish host families and foreign
 exchange students living with the families for up to one year. The theoretical background
 of the article is the ideal separation between money and family in Western society
 depicted by the anthropologists Maurice Bloch, David Schneider and James Carrier.
 The ethnographic material in the article is represented primarily by an extended case,
 and shows clearly that the separation is ideal, and that family life and finances are
 inseparable entities. The article analyses one reason why the exchange families are
 faced with financial challenges: Exchange organizations expect host parents to treat
 the exchange student as they treat their own child, and Westerners generally expect
 parents to treat their children in the same way. The article demonstrates that factors
 such as money and gifts affect the continuous creation of social relatedness in the
 “exchange families”. However, host parents’ intention of financially treating the
 exchange student like one of their children is doomed from the very start, since the
 financial conditions of the exchange student and the host siblings differ fundamentally.
 This difference challenges both the notion of sibling equality and the ideal relationship
 between parents as givers and children as receivers.

Adjusting Household Structure: School Enrollment Impacts of Child Fostering in Burkina Faso

Researchers claim that children growing up away from their biological parents may be at a disadvantage and have lower human capital investment. This paper measures the impact of child fostering on school enrollment and uses household and child fixed effects regressions to address the endogeneity of fostering. Data collection by the author involved tracking and interviewing the sending and receiving household participating in each fostering exchange, allowing a comparison of foster children with their non-fostered biological siblings. Foster children are equally likely as their host siblings to be enrolled after fostering and are 3.6 percent more likely to be enrolled than their biological siblings. Relative to children from non-fostering households, host siblings, biological siblings, and foster children all experience increased enrollment after the fostering exchange, indicating fostering may help insulate poor households from adverse shocks. This Pareto improvement in schooling translates into a long-run improvement in educational and occupational attainment.

Socialization in spectacled parrotlets (Forpus conspicillatus): how juveniles compensate for the lack of siblings

Socialization, that is, the process of the integration of an individual into the social system and the acquisition of basic social traits, has been studied in a variety of vertebrate species. Deprivation experiments have shown that the lack of early affiliative relationships has negative long-term effects on social behaviour and reproduction. Most studies emphasized the importance of the mother-infant relationship. However, it soon became evident that peer relationships to like-aged conspecifics, such as siblings and unrelated juveniles of nearly the same age, are also important for socialization. Whether individuals, deprived of one of these important social components, are able to compensate for this lack is not known. Here I tested the hypothesis that in spectacled parrotlets (Forpus conspicillatus), singletons (i.e., those that grew up without siblings) were able to compensate for this social lack by establishing and strengthening other relationships. In spectacled parrotlets socialization depends on the formation of long-lasting sibling groups. However, singletons without nest mates are quite common (about 6%), both in captivity and in nature. In this study I analysed the affiliative interactions with other group members of five singletons in comparison to eight siblings, from fledging to the 36th week after fledging, within a group of adult and juvenile conspecifics. In contrast to siblings, the singletons prolonged the relationships with their parents. Then they established a ”host sibling group” with other like-aged individuals. All singletons became well integrated into the group and established exclusive pair bonds. It is concluded that juvenile singletons of spectacled parrotlets are able to compensate for the lack of siblings by the development of alternative socialization tactics.

Socialisation Tactics of the Spectacled Parrotlet (Forpus Conspicillatus)

AbstractSpectacled parrotlets live in a complex system of individual relationships throughout their lives. The adults form exclusive pair bonds, addressing all friendly and sexual behaviour patterns to each other. Pair mates cooperate in agonistic situations. As long as they stay close together they hold the same rank-order position. In mate-choice experiments females (not males) significantly preferred a mate which formerly held a high social position. There are also non-exclusive pair bonds, which are far less stable than exclusive ones. Only exclusive pairs have a good chance to occupy a breeding cavity. All group members are synchronized in many of their activities, such as foraging, preening or resting. They are keenly interested in unusual activities of other group members. Social learning, including copying sexual techniques, seems to be essential. After fledging the parents keep their offspring at a distance from a very early stage. Instead of a close parent-offspring relationship the fledglings form sibling groups with their nest mates. Over a period of months siblings remain the main interaction partners for all friendly and playful activities. They also support one another in agonistic situations. In the first months of life even courtship feeding and sexual behaviour are addressed predominantly to siblings. Thus a pair-like relationship is established between siblings, anticipating the permanent pair bond of adults. Single fledglings, deprived of the experience of a sibling group, remained poorly integrated into the group. They developed alternative socialisation tactics, namely (1) joining a host group of unrelated siblings, (2) renewing a friendly partnership with the parents, (3) helping to protect and feed younger siblings or even unrelated fledglings and (4) seeking early partnership with unrelated group members. Out of 10 single fledglings only the one that was accepted by a host sibling group immediately after fledging became well integrated into the whole group and reproduced well. It is argued that sibling groups offer good opportunities for learning partnership and function as a safe basis for exploring the social environment. It is tentatively proposed that single fledglings have a decreased probability of reproductive success.

Adjustment processes of foreign exchange high school students in Japan

The main purpose of the present study was to excavate the adjustment problems of 93 high school exchange students in Japan. Questionnaires including Cornell Medical Index (CMI) were administered longitudinally. In addition, individual interviews were held with those who had failed to adjust to the Japanese society. As for the subjective psychosomatic symptoms manifested in CMI, there was no significant sex difference while Asians were successively found to be significantly more liable to diseases and less adjusted than non-Asians. The questionnaires other than CMI disclosed difficulties which exchange students found in adjusting at Japanese home, including delicate personal relationships with host siblings, apparent lack of affective gestures (hugs and kisses), and early curfew. In the meanwhile, language barrier and trifling rules constituted the primary difficulties they faced at host school. On account of prejudice against women, girls had more unpleasant experiences than boys. Through individual interviews, all of the early returners were found to have already had a basic problem in their home countries.