Like most phobias the causes of monophobia usually start in childhood. The most likely cause is being abandoned by a parent when you were a child. This tends to lead to a feeling of being unloved or unwanted. This leads to a feeling when we get older that people are going to leave and this causes a fear of being left alone. Basically the fear is that they won’t come back if they leave so there is a fear of being left alone.
Another common cause of monophobia is being abused as a child. Obviously the more people there are around the less likely it is that a child will be abused. This usually leads to a fear of what will happen when we are left alone. As we get older we continue to have this fear. In some cases this type of fear can start as adults. Children are