It's very difficult to answer that question. Most people believe in something that other people would call superstition, and in general, even though people don't like to admit it, or may not realize it, most people are superstitous in at least some area.
You should not believe in Superstitions. Superstitions is the product of ignorance among people. Many superstitions are not true.
People believe in superstitions because they are driven by fear.
Possibly because they were religious. People who are not religious do not normally believe in superstitions.
There are many superstitions regarding dragonflies in folk culture. Many people believe that the presence of a dragonfly means good luck.
Superstitions are beliefs supported only by rumor, not by factual observation. Rational people therefore do not believe such things.
because
They don't really. People who believe in superstitions are more prone to believe in the haunted houses thing than people who don't.
Yes, a lot of people still believe in superstitions, despite clear and contradictory evidence (or rational explanations for the origin of a superstition).
Yes, anybody that wishes to believe in superstitions can.
It has no survival value. People believe in in all kinds of things which others would consider superstitions. In most cases it does no harm.
Actually no, these are just superstitions that people believe.
There are a bunch of superstitions that people believe in. Things like black cats, the number 13, and walking under a ladder are the most common.