This paper describes experiments documenting significant variations in word usage patterns within social subgroups of AI researchers. As some phrases have very different collocational patterns than their constituent words, we look beyond occurrences of individual words, to consider word phrases. The mutual information statistic is used to measure the information content of phrases beyond that of their constituent words. Previous research has shown that some phrases are much more informative as word pairs outside topicadly defined subsets of a document corpus than within it. In this paper we show that individual universities provide an analogous, socicslly defined context in which locally-used phrases are "exported" into general AI vocabulary.