There is really not any way to know without the right study design. However, if there are multiple ways that each could cause the other, it may be a kind of dia

There is really not any way to know without the right study design. However, if there are multiple ways that each could cause the other, it may be a kind of dialectical process. For example, smiling can make you happy if you force yourself to do it. It also is the result of being happy.