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

Symmetry Is Beautiful

The Temporal Structure of Scientific Consensus Formation (Shwed and Bearman 2010) developed a procedure—which did not require expert judgment—to evaluate the level of contestation in scientific literatures. Examining different cases of consensus and contestation, we showed that science may progress in a spiral pattern that quickly generates new questions in new domains from recent answers (e.g., climate change research), stagnate around old questions in a cyclical pattern (e.g., smoking research in the 1950s), or entrench in a flat pattern responding to irrelevant external critiques (e.g., research on autism and vaccines). Bruggeman, Traag, and Uitermark (hereafter BTU) argue that without distinguishing between positive and negative citations, our procedure is of little value. They arrive at this conclusion by misunderstanding the role of network communities in our procedure. They then propose as an improvement a self-defeating solution that relies on distinguishing between postive and negative ties, requires expert evaluation, and destroys the possiblity of an unbiased evaluation. Avoiding that trap was the point of our article

The Hidden Costs of War: Exposure to Armed Conflict and Birth Outcomes

Abstract: Research suggests that prenatal exposure to environmental stressors has negative effects after birth. However, capturing causal effects is difficult because exposed women may be selected on unobserved factors. We use the 2006 Israel-Hezbollah war as a natural experiment and a siblings fixed-effects methodology to address unobserved selectivity by comparing exposed and unexposed births of the same mother. Findings indicate that exposure to war in early and mid-pregnancy lowers birth weight and increases the probability of low birth weight. The effect is not driven by geographic sorting, migration, or increased miscarriages. Given that birth weight predicts health, developmental, and socioeconomic outcomes, prenatal exposure to acute stress may have long-term effects over the life course