Reverse causality is the potential for the effect of greater religiosity on positive behavioral outcomes to work in the opposite direction. In other words, it is possible that behavioral outcomes affect religious participation and beliefs. For example, high church attendance can be associated with a higher probability of marriage at one time point. However, it could also be that marriage encourages greater religious attendance. While reverse causality is an issue in cross-sectional studies that only examine church attendance and marriage at the same time point, using longitudinal data that follow study participants over time can help establish the direction of the effects from religiosity to a behavioral outcome because the ordering of the events are known. Longitudinal data also allow researchers to study how changes in religiosity can affect changes in behavior.