Q: Are superstitions mental rules?
No, not rules but mental formations. Generally a superstition originates in an experience. For instance, there is a certain superstition in Europe, and you are told: “Never walk under a ladder, it will bring you ill-luck.” It is probable that someone walked under a ladder and the ladder slipped and fell upon him, and the story starts off like that. It can happen that this is a repeated experience, for, in fact, if a ladder is badly placed and you pass underneath it could fall at that very moment, and that would bring ill-luck! There are innumerable superstitions of this kind. They depend upon the countries, besides; these things are quite local and one may even find contradictory superstitions in different countries. In certain countries if you see a black cat, it is a sign that a catastrophe will come. In others if you see a black cat, it means that something very fine will happen! If you put things together you will come to the conclusion that nothing at all will happen to you! It is like that. Almost all superstitions are the result of an experience that is quite local, occasional, exceptional, which has been raised into a mental principle. It is a mental formation, it is not a rule.
Now, there are other instances, as for example a large number of religious rules which are founded solely on hygienic principles, on medical knowledge, and have been raised into religious principles, for that was the only way to make people observe them…. But in this way there is that constant fear at the back of their minds that something bad will happen to them due to God’s anger.
Ref : Questions and Answers 1953