Theory-driven text analysis has made extensive use of psychological concept dictionaries, leading to a wide range of important results. These dictionaries have generally been applied through word count methods which have proven to be both simple and effective. In this paper, we introduce Distributed Dictionary Representations (DDR), a method that applies psychological dictionaries using semantic similarity rather than word counts. This allows for the measurement of the similarity between dictionaries and spans of text ranging from complete documents to individual words. We show how DDR enables dictionary authors to place greater emphasis on construct validity without sacrificing linguistic coverage. We further demonstrate the benefits of DDR on two real-world tasks and finally conduct an extensive study of the interaction between dictionary size and task performance. These studies allow us to examine how DDR and word count methods complement one another as tools for applying concept dictionaries and where each is best applied. Finally, we provide references to tools and resources to make this method both available and accessible to a broad psychological audience. Keywords Methodological innovation · Text analysis · Semantic representation · Dictionary-based text analysisElectronic supplementary material The online version of this article

Needle exchange services reduce the spread of disease. However, these services lack public support, in part because of moral misgivings. Research suggests that moral attitudes are grounded in at least five "foundations": (1) Care, (2) Fairness, (3) Loyalty, (4) Authority, and (5) Purity. Understanding the moral basis of needle exchange attitudes could inform public health messaging. Participants in the study (n = 5,369) completed a questionnaire on needle exchange attitudes (NEA) and also completed the Moral Foundations Questionnaire (MFQ). The NEA had high internal reliability. NEA was most strongly predicted (in the negative direction) by individual level of Purity concerns, followed by (in the positive direction) Care concerns. Moral Foundations Theory provides a framework for understanding moral attitudes towards needle exchange. Moral misgivings about needle exchange are associated with Purity concerns. If this association is causal, it may offer insight into how to build wider support for needle exchange programs.