The Japanese, as I’ve often written, are a group-oriented people, and it’s interesting to observe the subtle body language that goes back and forth when people get together. If you have a bag of potato chips that you want to offer to friends, the correct way to do it is to open it “party-biraki” style, placing the bag with the seal facing upwards then ripping the entire bag open so that the contents sit on the opened wrapping. This makes it convenient for everyone to grab some chips, but it also helps your guests knock down social barriers that keep them from relaxing and having fun. The Japanese have a tendency to avoid taking something that’s offered to them due to enryo, translatable as restraint, reserve, or as a verb, to refrain from doing something, and it can be difficult to get people at a party to lighten up at first. By opening the bag so that the contents will go to waste if your guests don’t eat, you give them an excuse to dig in.
Some people don’t need help eating potato chips.