“If you eat white chocolate, you’ll turn purple.”
The informant was made aware of this belief when she was about seven years old. This was one of several stories she was told by her cousins, who were eight and 12 at the time of the telling. They had passed this on to the informant because they were vouching for it’s validity, and because it had become popular in their school.
At her cousins’ school, there was a stigma against white chocolate because select students had deemed it “gross” and admonished people for eating it by saying that only “gross” people would eat it. This small group—and later, the general populace—believed that white chocolate was not “real” chocolate. This forced the informant to abstain from eating chocolate out of fear of being punished for eating it (by being made purple). She eventually lost her taste for white chocolate over the period of time that she was afraid to eat it. This represents a way for a powerful minority group to assimilate the beliefs of the larger majority. Fear of ridicule, a powerful emotion for grade-school children, served as the driver for pushing the beliefs of those that took charge.
This saying is powerful in its ability to alter behaviors. In the hands of a few, this functioned almost as propaganda getting the masses on board with a belief they may have rejected without fear. Even for those who do not believe the warning, the shaming that it fosters can remain effective.
For a similar story about shaming and color changing, (and specifically, the color purple) see: