Historical time in the age of big data: Cultural psychology, historical change, and the Google Books Ngram Viewer.

Launched in 2010, the Google Books Ngram Viewer offers a novel means of tracing cultural change over time. This digital tool offers exciting possibilities for cultural psychology by rendering questions about variation across historical time more quantitative. Psychologists have begun to use the viewer to bolster theories about a historical shift in the United States from a more collectivist to individualist form of selfhood and society. I raise 4 methodological cautions about the Ngram Viewer's use among psychologists: (a) the extent to which print culture can be taken to represent culture as a whole, (b) the difference between viewing the past in terms of trends versus events, (c) assumptions about the stability of a word's meaning over time, and (d) inconsistencies in the scales and ranges used to measure change over time. The aim is to foster discussion about the standards of evidence needed for incorporating historical big data into empirical research.