Peter S. Bearman

Chains of Affection: The Structure of Adolescent Romantic and Sexual Networks 1

This article describes the structure of the adolescent romantic and sexual network in a population of over 800 adolescents residing in a midsized town in the midwestern United States. Precise images and measures of network structure are derived from reports of relationships that occurred over a period of 18 months between 1993 and 1995. The study offers a comparison of the structural characteristics of the observed network to simulated networks conditioned on the distribution of ties; the observed structure reveals networks characterized by longer contact chains and fewer cycles than expected. This article identifies the micromechanisms that generate networks with structural features similar to the observed network. Implications for disease transmission dynamics and social policy are explored.

Promising the future : Virginity pledges and first intercourse

Since 1993, in response to a movement sponsored by the Southern Baptist Church, over 2.5 million adolescents have taken public “virginity” pledges, in which they promise to abstain from sex until marriage. This paper explores the effect of those pledges on the transition to first intercourse. Adolescents who pledge are much less likely to have intercourse than adolescents who do not pledge. The delay effect is substantial. On the other hand, the pledge does not work for adolescents at all ages. Second, pledging delays intercourse only in contexts where there are some, but not too many, pledgers. The pledge works because it is embedded in an identity movement. Consequently, the pledge identity is meaningful only in contexts where it is at least partially nonnormative. Consequences of pledging are explored for those who break their promise. Promise breakers are less likely than others to use contraception at first intercourse.

Diagnostic change and the increased prevalence of autism

BACKGROUND Increased autism prevalence rates have generated considerable concern. However, the contribution of changes in diagnostic practices to increased prevalence rates has not been thoroughly examined. Debates over the role of diagnostic substitution also continue. California has been an important test case in these controversies. The objective of this study was to determine the extent to which the increased prevalence of autism in California has been driven by changes in diagnostic practices, diagnostic substitution and diagnostic accretion. METHODS Retrospective case record examination of 7003 patients born before 1987 with autism who were enrolled with the California Department of Developmental Services between 1992 and 2005 was carried out. Of principal interest were 631 patients with a sole diagnosis of mental retardation (MR) who subsequently acquired a diagnosis of autism. The outcome of interest was the probability of acquiring a diagnosis of autism as a result of changes in diagnostic practices was calculated. The probability of diagnostic change is then used to model the proportion of the autism caseload arising from changing diagnostic practices. RESULTS The odds of a patient acquiring an autism diagnosis were elevated in periods in which the practices for diagnosing autism changed. The odds of change in years in which diagnostic practices changed were 1.68 [95% confidence interval (CI) 1.11-2.54], 1.55 (95% CI 1.03-2.34), 1.58 (95% CI 1.05-2.39), 1.82 (95% CI 1.23-2.7) and 1.61 (95% CI 1.09-2.39). Using the probability of change between 1992 and 2005 to generalize to the population with autism, it is estimated that 26.4% (95% CI 16.25-36.48) of the increased autism caseload in California is uniquely associated with diagnostic change through a single pathway--individuals previously diagnosed with MR. CONCLUSION Changes in practices for diagnosing autism have had a substantial effect on autism caseloads, accounting for one-quarter of the observed increase in prevalence in California between 1992 and 2005.

Dynamics of Political Polarization

This article accounts for two puzzling paradoxes. The first paradox is the simultaneous absence and presence of attitude polarization—the fact that global attitude polarization is relatively rare, even though pundits describe it as common. The second paradox is the simultaneous presence and absence of social polarization—the fact that while individuals experience attitude homogeneity in their interpersonal networks, their networks are characterized by attitude heterogeneity. These paradoxes give rise to numerous scholarly arguments. By developing a formal model of interpersonal influence over attitudes in a context where individuals hold simultaneous positions on multiple issues, we show why these arguments are not mutually exclusive and how they meaningfully refer to the same social setting. The results from this model provide a single parsimonious account for both paradoxes. The framework we develop may be generalized to a wider array of problems, including classic problems in collective action.

Ascription into Achievement: Models of Career Systems at Lloyds Bank, 1890-1970

Optimal matching algorithms are used to model the transformation of career systems in a large British bank (Lloyds) from 1890 to 1970. The authors first model the breakdown of the traditional ascriptive, status-based system, and then identify a more dynamic, achievement-based system, and then identify a more dynamic, achievement-based system as its replacement. By relating the structure of careers to organizational growth and social change, the authors explore how the modern achievement career came about. More broadly, they argue that optimal matching enables one to see clearly the multiple time frames that are necessarily intercalated into career systems and hence provides new insights into the discontinuous and contingent nature of organizational change.

Age of diagnosis for autism: individual and community factors across 10 birth cohorts

Background The incidence of autism rose dramatically between 1992 and 2001, while the age at which children were first diagnosed declined. During this period the size and composition of the autism caseload has changed, but little is known about whether the factors associated with the timing of diagnosis may also have shifted. Using a multilevel analysis strategy, the individual and community-level factors associated with age of diagnosis were modelled across 10 birth cohorts of California children. Methods Linked birth and administrative records on 17 185 children with diagnoses of autistic disorder born in California between 1992 and 2001 and enrolled with the California Department of Developmental Services (DDS) were analysed. Information on cases, their parents and their residential location were extracted from birth and DDS records. Zip codes of residence were matched to census data to create community-level measures. Multilevel linear models were estimated for each birth cohort, with individual-level effects for sex, race, parental characteristics, poverty status, birth order and symptom expression. At the community level measures of educational and economic composition, local autism prevalence and the presence of a child psychiatrist were included. Results Children with highly educated parents are diagnosed earlier, and this effect has strengthened over time. There is a persistent gap in the age of diagnosis between high and low socioeconomic status (SES) children that has shrunk but not disappeared over time. Conclusion Routine screening for autism in early childhood for all children, particularly those of low SES, is necessary to eliminate disparities in early intervention.

Becoming a Nazi: A model for narrative networks

Abstract This article illustrates a strategy for representing and analyzing narratives as networks. The strategy that we use considers narrative sequences as networks. Elements are treated as nodes which are connected by narrative clauses, represented by arcs. By representing complex event sequences as networks, inducing ‘narrative networks’, it is possible to observe and measure new structural features of narratives. The narratives we focus on are autobiographical accounts of becoming, and being, a Nazi. The substantive idea that we develop in this article is that the observable narrative structure of life stories can provide insight into the process of identity formation. We illustrate our approach to narrative networks by analyzing a single story that, in conjunction with the analysis of other stories, yields a set of insights into becoming and being .

The Temporal Structure of Scientific Consensus Formation

This article engages with problems that are usually opaque: What trajectories do scientific debates assume, when does a scientific community consider a proposition to be a fact, and how can we know that? We develop a strategy for evaluating the state of scientific contestation on issues. The analysis builds from Latour’s black box imagery, which we observe in scientific citation networks. We show that as consensus forms, the importance of internal divisions to the overall network structure declines. We consider substantive cases that are now considered facts, such as the carcinogenicity of smoking and the non-carcinogenicity of coffee. We then employ the same analysis to currently contested cases: the suspected carcinogenicity of cellular phones, and the relationship between vaccines and autism. Extracting meaning from the internal structure of scientific knowledge carves a niche for renewed sociological commentary on science, revealing a typology of trajectories that scientific propositions may experience en route to consensus.

The social structure of suicide

A parsimonious structural model of the four forms of suicide — egoism, altruism, anomie, and fatalism — defined in DurkheimsSuicide is developed. The model explicitly defines the structural position of each form of suicide by focusing on duality of social structure, while retaining an analytic distinction between social integration and normative regulation. A payoff from this approach is that fatalism and anomie are interpreted in the same framework as altruism and egoism. The result is a consistent account of the four forms of suicide that is faithful to Durkheims intentions to account for the aggregate suicide rate without recourse to the motivations of actors.

Medical school gift restriction policies and physician prescribing of newly marketed psychotropic medications: difference-in-differences analysis

Objective To examine the effect of attending a medical school with an active policy on restricting gifts from representatives of pharmaceutical and device industries on subsequent prescribing behavior. Design Difference-in-differences approach. Setting 14 US medical schools with an active gift restriction policy in place by 2004. Participants Prescribing patterns in 2008 and 2009 of physicians attending one of the schools compared with physicians graduating from the same schools before the implementation of the policy, as well as a set of contemporary matched controls. Main outcome measure Probability that a physician would prescribe a newly marketed medication over existing alternatives of three psychotropic classes: lisdexamfetamine among stimulants, paliperidone among antipsychotics, and desvenlafaxine among antidepressants. None of these medications represented radical breakthroughs in their respective classes. Results For two of the three medications examined, attending a medical school with an active gift restriction policy was associated with reduced prescribing of the newly marketed drug. Physicians who attended a medical school with an active conflict of interest policy were less likely to prescribe lisdexamfetamine over older stimulants (adjusted odds ratio 0.44, 95% confidence interval 0.22 to 0.88; P=0.02) and paliperidone over older antipsychotics (0.25, 0.07 to 0.85; P=0.03). A significant effect was not observed for desvenlafaxine (1.54, 0.79 to 3.03; P=0.20). Among cohorts of students who had a longer exposure to the policy or were exposed to more stringent policies, prescribing rates were further reduced. Conclusion Exposure to a gift restriction policy during medical school was associated with reduced prescribing of two out of three newly introduced psychotropic medications.