I think it is human nature to be be superstitious, whether you admit it or not, or call it that or not. Everyone talks about "luck", or perhaps have items they consider "lucky". Athletes are known for the rituals they follow. Some athletes have articles of clothing they wear or won't wash if they are on a winning streak. Dale Earnhardt had a "lucky penny" glued to his dashboard when he had a particular important win. Tom Brady wouldn't cut his hair when the Patriots were on a winning streak one year.
My Granny was a small but mighty woman, even imposing at a petite 4'8". Even she had superstitions. One passed down through her beliefs was that all Christmas decorations be taken down and put away before midnight New Year's eve. Before the new year arrives, this must be done or someone in the house may die in the new year. I remember fearing this and that something may get overlooked...then what?! Well, I still observe this, but not as strictly. As a Catholic, I now like to leave the nativity out until Epiphany. (Granny was a strict Baptist, as was I growing up.)
It was also not wise to put up a calendar for the new year until the 1st day of the new year. You did not want to bring the bad things from the old year into the new year. You want to start fresh.
Granny also delivered many babies in western Tennessee, in her day (early 1900's). She believed in the "veil" some infants are born with as being "lucky" for that child. The veil usually was over the infants face. Granny would take this and put it on a Bible for the mother, to preserve it for her and the child. To destroy it was considered very bad luck, as it was an omen of greatness for the child.
These were Granny's superstitions. Seven year bad luck for breaking a mirror, throwing salt over your left shoulder however, as were many others, considered "old wives tales", not to be taken seriously.
Superstitions are often family traditions, which is also common in many cultures.