I took this picture from the internet.The chopsticks is a lever.The point where two chopsticks crossed is the pivot of the lever.In ancient times, our ancestors liked to steam or boil food. It was difficult for them to use spoons to dip vegetables in the soup.So they invented the chopsticks as it is easier for them to use it to dip vegetables.We hold the chopsticks with our thumb, index finger, middle finger and third finger. One stick is against your third finger and the other leans on your middle finger.When we pick the food, we use our index finger and middle finger to control the chopsticks and nip food.It will be hard to keep using spoon if they did not invent it.