Researchers are often interested in comparing correlations between variables at different levels of analysis (e.g., individual and organizational) to determine if the same relationship holds across the levels. A special situation emerges when correlations at higher levels are based on aggregated data. This article contains an analysis of the nature of the relationship between correlations based on individual-level data and correlations based on aggregated data from individuals. In particular, the conditions under which differences between individual correlations and correlations based on aggregates represent statistical artifacts or meaningful differences are explored.