The Effect of Social Responsiveness on Infants' Object‐Directed Imitation

Previous research has demonstrated that social interactions underlie the development of object‐directed imitation. For example, infants differentially learn object action sequences from a live social partner compared to a social partner over a video monitor; however, what is not well understood is what aspects of social interactions influence social learning. Previous studies have found variable influences of different types of caregiver responsiveness on attention, language, and cognitive development. Therefore, the purpose of this study was to examine how the responsive style of a social partner influenced the learning of object‐directed action sequences. Infants interacted with either a sensitive or redirective experimenter before the learning trial. Results revealed infants changed their patterns of engagement; infants interacting with a sensitive experimenter had longer periods of attentional engagement than infants interacting with a redirective experimenter. Furthermore, during the learning trial, the amount of sensitivity during interaction with the social partner predicted learning scores. These findings suggest that infants' attention is influenced by social partners' interactive style during ongoing interaction, which subsequently affects how infants learn from these social partners.     

Improving Risk-Based Decision Making for Terrorism Applications

How can we best allocate limited defensive resources to reduce terrorism risks? Dillon et al.'s Antiterrorism Risk-Based Decision Aid (ARDA) system provides a useful point of departure for addressing this crucial question by exhibiting a real-world system that calculates risk reduction scores for different portfolios of risk-reducing countermeasures and using them to rank-order different possible risk mitigation alternatives for Navy facilities. This comment points out some potential limitations of any scoring system that does not take into account risk externalities, interdependencies among threats, uncertainties that are correlated across targets, and attacker responses to alternative allocations of defensive resources. In at least some simple situations, allocations based on risk reduction scores and comparisons can inadvertently increase risks by providing intelligent attackers with valuable information, or they can fail to reduce risks as effectively as nonscoring, optimization-based approaches. These limitations of present scoring methods present exciting technical challenges and opportunities for risk analysts to develop improved methods for protecting facilities and infrastructure against terrorist threats.     

Could Removing Arsenic from Tobacco Smoke Significantly Reduce Smoker Risks of Lung Cancer?

If a specific biological mechanism could be determined by which a carcinogen increases lung cancer risk, how might this knowledge be used to improve risk assessment? To explore this issue, we assume (perhaps incorrectly) that arsenic in cigarette smoke increases lung cancer risk by hypermethylating the promoter region of gene p16INK4a, leading to a more rapid entry of altered (initiated) cells into a clonal expansion phase. The potential impact on lung cancer of removing arsenic is then quantified using a three‐stage version of a multistage clonal expansion (MSCE) model. This refines the usual two‐stage clonal expansion (TSCE) model of carcinogenesis by resolving its intermediate or “initiated” cell compartment into two subcompartments, representing experimentally observed “patch” and “field” cells. This refinement allows p16 methylation effects to be represented as speeding transitions of cells from the patch state to the clonally expanding field state. Given these assumptions, removing arsenic might greatly reduce the number of nonsmall cell lung cancer cells (NSCLCs) produced in smokers, by up to two‐thirds, depending on the fraction (between 0 and 1) of the smoking‐induced increase in the patch‐to‐field transition rate prevented if arsenic were removed. At present, this fraction is unknown (and could be as low as zero), but the possibility that it could be high (close to 1) cannot be ruled out without further data.     

Urban forest cover of the Chicago region and its relation to household density and income

Urban forests and herbaceous open space play a vital role in the environmental and aesthetic health of cities, yet they are rarely identified in land-use inventories of urban areas. To provide information on urban forests and other vegetative land cover in Illinois cities, Landsat Thematic Mapper (TM) data from June 27, 1988, were classified for the Chicago metropolitan region (9,717 km²). Ten land-cover classes were identified, including two types of forestland (occupying 5.8% of the total area), residential land with trees (14.6%) or without trees (7.8%), cropland (37.5%), two types of grassland (7.7%), urban with impervious surfaces (23.1%), water (1.6%), and miscellaneous vegetation (2.1%). Correlation analyses indicated that household income and household density are strongly related to land covers in the region, particularly those with tree cover and urbanized land. Population changes for 1980–1985 and 1985–2010 (projected) show a pattern of increasing density in the urbanized zone concurrent with continued urban sprawl, primarily into current cropland.     

Social theory and the de-escalation of international conflict*

Are we like the mothers and fathers at Jonestown, with the cyanide in place, rehearsing for suicide-murder? Daniel Ellsberg (1981) observes that the marchers protesting nuclear weapons are doing what the mothers and fathers in Jonestown waited too long to say ‘No! Not our children! This is craziness; we won't be part of it.’ He writes that ‘It is none too soon to be saying this to the President/Prime Minister/Chairman Jim Jones's of the world; nor is it, yet, too late.’ How did we get into a place that even resembles Jonestown: And more importantly, how do we get out of it? Social theory should help provide answers to such questions, but does not obviously do so. In the first part of this paper I discuss an emerging theoretical paradigm that has particular relevance for understanding how international conflicts increase and decrease in intensity. Then I apply that paradigm to instances of international conflict de-escalation, focusing on declines in tension and hostility between the Soviet and American governments and the Israeli and Egyptian governments. Finally, I will point to some implications of the discussion for social theory and for international policy.     

On the multivariate structure of wellbeing

A mapping sentence is provided for defining the universe of observations of wellbeing. According to this, assessment of wellbeing is attitudinal. Data from several studies verify that the First Law of Attitude holds for wellbeing. These data also show the structure of the interrelationships among the variables to be that of intermeshing cylindrexes, in an SSA space of four dimensions. Areas of life play the role of polarizing facets, while self-versus-community and situation-versus-treatment serve as axial facets. Modulating facets include primary-to-secondary interaction, and generality-to-specificity.     

A Comparative Analysis of Propositions Describing Social Movement Organizations*

Natural history, observational, and interview data from a study of two anti-pornography crusades and the social movement organizations which created and directed them are used to assess nine propositions formulated by Zald and Ash (1966) concerning the structure and dynamics of social movement organizations. The Zald-Ash propositions were formulated from the literature on national, established social movement organizations. This paper explores the applicability of the propositions to those organizations which are small and emerging. The propositions are generally supported. Discrepancies are accounted for by the significant influence of leadership orientation, goal specificity, and incentive structure in determining other structural and dynamic characteristics of small or emerging social movement organizations.