One of the classics of the literature, the Müller-Lyer illusion, showed that where you grew up would determine to what degree you would fall prey to the illusion that these two lines are different in length:
Researchers found that Americans perceive the line with the ends feathered outward (B) as being longer than the line with the arrow tips (A). San foragers of the Kalahari, on the other hand, were more likely to see the lines as they are: equal in length. Subjects from more than a dozen cultures were tested, and Americans were at the far end of the distribution—seeing the illusion more dramatically than all others.