Recent work argues that changes in people's responses to the same question over time should be thought of as reflecting a fixed baseline subject to temporary local influences, rather than durable changes in response to new information. Distinguishing between these two individual-level process-a settled dispositions model and an active updating model-is important because these individual-level processes underlie different theories of population-level social change. This article introduces an alternative method for adjudicating between these two models based on structural equation modeling. This model provides a close fit to the theoretical models outlined in previous work. Applying this method to more than 500 questions in the General Social Survey's three-wave panels, we find even stronger evidence than previous work that most survey responses reflect settled dispositions developed prior to adulthood.