The Connection Between Moral Positions and Moral Arguments Drives Opinion Change

On moral issues, it is well-known that liberals and conservatives often tend to take opposing positions. However, the connection between ideology and positions is not absolute, as evidenced by public opinion moving dramatically on some issues (e.g., gay rights) while not moving on other issues (e.g., abortion). To understand this phenomenon, we here characterize positions on 74 moral issues by analyzing which moral foundations people draw on to argue for a given position. We then present a mathematical model of how opinions in a population change on an issue depending on its characteristics. For any given issue, the model predicts both which should be the liberal position and how public opinion should shift over time. In an analysis of over 40 years of data from the General Social Survey, we find the model predictions to be strongly supported. One finding is that liberals are generally winning the culture war