Question

why people believe in superstition

Answer 1

Superstitions are some acts which had reason when it were performed in the past. Now-a-days, the reason is lost and they are blindly followed.

Right from birth, people feed you with superstitions and fear. Over the years, you get so used to these superstitions and fear that you won’t deviate from them so easily.

Consider a world’s biggest superstition where people ask you to believe or have faith in god. This is a superstition. I know, most of the people won’t believe this. I can give explanations, but it would be a debt rather than an answer.

Answer 2

We can see a lot of superstitions everywhere.
There are some messages that ask you to 'forward this to 10 people and something good will happen in the next 24 hours’.This superstitions are followed on WhatsApp, Facebook etc.
1 People hate to find themselves lacking control and hence as a result some of them start to believe in superstitious ideas in order to feel in control. 
2.A very important reason is that We are really not that much “Intelligent” in everything. Mostly we try to obey or copy what others have told us or others are doing. Eventually, Superstition is followed due to this reason.
Hence , Superstitions need to be avoided as soon as possible which might take place in future.
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This is the answer.