Blue Seven
Get some random people together and ask them to name a random color. Chances are, they will say "Blue." And this phenomena doesn't care about culture. Your random people overwhelmingly will say "Blue."
Now, take your same group of random people and ask them to pick a number between 1 and 10. Your results will have a disporpotionate number of people who pick "Seven." As with the color phenomena above, it does not matter what culture, country, or who you pick. The results sway towards the number "Seven."
Why?
Back in the 70s[1] a bunch of big heads got together and had a study. They asked a bunch of people the color/number question and recorded the results. As predicted above, the majority of respondents said "blue" and "seven."
The scientists went on to waste a ton of tax payer funded money to put together some book or thesis or some other dumb crap telling us that random people tend to pick blue and seven.
However, much like most science, it was all bullshit. What the big heads and other science folk didn't account for was the fact that the majority of humans are NPCs who can't escape their programming.
Or, perhaps those scientists DID know what they were doing. A fat government grant and a ridiculous study involving human automatons is an excellent way to justify a career bolstered by a worthless degree. The truth should never get in the way of a paycheck and the esteem bestowed upon you by your equally worthless collegues.