Life Course Status and Exchanges of Support Between Young Adults and Parents

The authors investigated intergenerational support exchanges in relation to young adults' life course status. In a sample of 2,022 young adults (ages 18–34 years) in The Netherlands, single young adults reported receiving more advice from parents than married young adults, and those with children of their own received more practical support. Married young adults and young adults with children provided less support to parents than, respectively, single young adults and young adults without children. Congruent with the life course perspective, the authors' findings suggest that the intergenerational support network is both durable and flexible, responding to the resources and needs associated with an individual's life course status.     

Peer Group Affiliation of Children: The Role of Perceived Popularity,Likeability, and Behavioral Similarity in Bullying

To understand children's peer group affiliation, this study examined to what extent children in naturally occurring groups resemble each other on bullying, likeability, and perceived popularity. Participants were fourth‐ to sixth‐grade pupils (N = 461). Peer groups were identified using the social cognitive map procedure. Resemblance on bullying, likeability, and perceived popularity was evaluated by means of variance components models. Resemblance in peer groups was strongest for perceived popularity, followed by bullying and likeability. Moreover, resemblance on bullying could for a large part be attributed to the high‐perceived popularity of the group, and to a lesser extent, to the low likeability of the group. It is concluded that children showing bullying seem to affiliate with each other most of all to attain or maintain their position in a perceived popular peer group. Results stress the importance of considering the functionality of bullying from a group perspective.     

Soil Nutrient Depletion and Population Growth in Sub-Saharan Africa: A Malthusian Nexus?

Soil nutrient mining and other forms of soil degradation threaten future soil productivity, especially in sub-Saharan Africa (SSA). Data from 36 countries in SSA show a significant relationship at the supra-national level between soil nutrient depletion (including erosion), reduced fallow periods, and population pressure and thus illustrate the unsustainable population-agriculture-environment nexus on the continent which so far has been described in case studies only. It appears that Malthusian mechanisms are at work, despite encouraging indications of farmers' concerns and adaptation to changing conditions. It is agreed that a re-examination of the common land degradation assessments and farmers' response to changing conditions would be useful, however, this should not delay other recommended interventions.     

Multivariate non-linear time series modelling of exposure and risk in road safety research

Summary.  A multivariate non-linear time series model for road safety data is presented. The model is applied in a case-study into the development of a yearly time series of numbers of fatal accidents (inside and outside urban areas) and numbers of kilometres driven by motor vehicles in the Netherlands between 1961 and 2000. The model accounts for missing entries in the disaggregated numbers of kilometres driven although the aggregated numbers are observed throughout. We consider a multivariate non-linear time series model for the analysis of these data. The model consists of dynamic unobserved factors for exposure and risk that are related in a non-linear way to the number of fatal accidents. The multivariate dimension of the model is due to its inclusion of multiple time series for inside and outside urban areas. Approximate maximum likelihood methods based on the extended Kalman filter are utilized for the estimation of unknown parameters. The latent factors are estimated by extended smoothing methods. It is concluded that the salient features of the observed time series are captured by the model in a satisfactory way.     

Differences in adolescents’ motivations for indirect,direct, and hybrid peer defending

Adolescents’ defending of peers who are being bullied—or peer defending—was recently found to be a heterogeneous behavioral construct. The present study investigated individual differences in adolescents’ motivations for executing these indirect, direct, and hybrid defending behaviors. In line with the literature on bullying as goal‐directed strategic behavior, we adopted a social evolution theory framework to investigate whether these peer‐defending behaviors could qualify as goal‐directed strategic prosocial behaviors. A sample of 549 Dutch adolescents (49.4% boys; M_age = 12.5 years, SD = 0.6 years) participated in this study. Their peer reported defending behaviors (including bullying behavior as a control variable) and the following behavioral motivations were assessed: (a) agentic and communal goals (self‐report), (b) prosocial and coercive social strategies (peer report), and (c) altruistic and egocentric motivations for prosocial behavior (self‐report). The outcomes of hierarchical linear regression analyses suggest that adolescents’ motivations for executing the different subtypes of peer defending partially overlap but are also different. While indirect defending was fostered by genuine concerns for victims’ well‐being, direct defending was more motivated by personal gains. Hybrid defending combined favorable aspects of both indirect and direct defending as a goal‐directed, strategic, and altruistically motivated prosocial behavior. The implications of these findings are discussed.     

Measuring Infant‐Mother Attachment: Is the Strange Situation Enough?

The purpose of this study was to examine the validity of a new procedure for assessing infant-mother attachment. Sixty children (34 in child care) and their mothers were seen in the Strange Situation (SS) at 17 months and in a new attachment assessment, the California Attachment Procedure (CAP), which does not involve mother-child separations, at 18 months. Overall, children were more likely to be classified as secure in the CAP (83% vs. 67%), but this was particularly true for children with experience in routine nonmaternal care. Of the children in nonmaternal care who were insecure in the SS, 91% were secure in the CAP, whereas of the maternal-care children who were insecure in the SS, only 44% were secure in the CAP. Attachment security in the CAP was more highly correlated with observed maternal sensitivity than was attachment security in the SS, particularly for children in nonmaternal care.     

Homosexual role separation: Implications for analyzing and modeling the spread of HIV

The analysis of the spread of HIV in homosexual populations must be based on knowledge of all factors which promote or inhibit transmission. Recently, data were reported from the Amsterdam cohort study that imply that sexual role separation and the changes therein should be taken into account in analyzing and modeling the spread of HIV. In this paper, a role separation mixing model is described and linked to data from the Amsterdam cohort. The model allows one to study the impact of homosexual role separation on the spread of HIV. The homosexual men are classified into four sexual subgroups based on the preference for: 1) no anal intercourse; 2) anal insertive only; 3) anal receptive only; 4) both insertive and receptive. The analysis accounts for variability and change in homosexual role behavior and loss to follow up. The results support the conjecture that there are large differences between the risks of receptive and insertive anal intercourse, with the latter carrying only minimal risk. The analysis indicates that the spread of HIV is mostly restricted to subgroup 4, the largest and sexually most active subgroup. In this subgroup, the estimated probability of HIV transmission from an infected insertive partner (in subgroup 2 or 4) to a receptive susceptible (in subgroup 4) is between 1 and 5 percent (assuming a closed cohort).     

Model-based measurement of latent risk in time series with applications

Summary.  Risk is at the centre of many policy decisions in companies, governments and other institutions. The risk of road fatalities concerns local governments in planning countermeasures, the risk and severity of counterparty default concerns bank risk managers daily and the risk of infection has actuarial and epidemiological consequences. However, risk cannot be observed directly and it usually varies over time. We introduce a general multivariate time series model for the analysis of risk based on latent processes for the exposure to an event, the risk of that event occurring and the severity of the event. Linear state space methods can be used for the statistical treatment of the model. The new framework is illustrated for time series of insurance claims, credit card purchases and road safety. It is shown that the general methodology can be effectively used in the assessment of risk.     

Ex Post Problems in Buyer–Supplier Transactions: Effects of Transaction Characteristics, Social Embeddedness, and Contractual Governance

This paper focuses on ex post governance of inter-firm transactions. We develop and test hypotheses on the occurrence of ex post problems like delivery delays, inferior quality, and insufficient service in buyer–supplier transactions. Our hypotheses address effects of transaction characteristics, of social embeddedness, and of contractual governance on the occurrence of problems. Other than earlier research on embeddedness effects in this field, we consider not only effects of dyadic embeddedness but also effects of network embeddedness. We test hypotheses using rich survey data on more than 1200 purchases of information technology (IT) products: hardware and software, both standard and complex. We find evidence for effects of transaction characteristics on the occurrence of problems, while our data do not support hypotheses on effects of contractual governance. Our data provide rather consistent support for hypotheses on the effects of embeddedness. Specifically, we find evidence that network embeddedness reduces problems.     

Bullying and the Need to Belong: Early Adolescents' Bullying-Related Behavior and the Acceptance they Desire and Receive from Particular Classmates

Based on the notion that one of the motives underlying children's antisocial behavior is their need to belong to particular peers, it was examined how each of four types of bullying‐related behavior would be related to the acceptance that 10 to 13‐year‐old children desired and received from same‐ and other‐sex children with different bullying‐related behavioral styles. Bullying‐related behavior was assessed using a peer nomination procedure. Children rated the importance of being accepted by each particular classmate and their own acceptance of these same classmates. Among boys, antisocial involvement in bullying was related to a desire to be accepted by other antisocial boys and to actually being rejected by boys in general. Among girls, antisocial involvement in bullying was related to a desire to be accepted by boys in general.