Dynamic social impact theory suggests that culture is created and shaped by local social influence as defined by four phenomena: (i) clustering, or regional differences in cultural elements; (ii) correlation, or emergent associations between elements; (iii) consolidation, or a reduction in variance; and (iv) continuing diversity. This article describes dynamic social impact theory and its propositions and reviews research supporting its predictions using a variety of methodologies and several types of cultural elements. This research suggests that cultures can be created and changed from the bottom-up through everyday communication with neighbors, friends, and coworkers. Attributes that are more important, observable, and demonstrable and less heritable may be more likely to spread and differentiate cultures than others.