* Hair follicles are individual: Each hair grows from its own individual follicle. Plucking a hair only affects that specific follicle.
* Grey hair is determined by pigment: Hair turns grey when the pigment-producing cells (melanocytes) in the follicle stop producing as much melanin. This is usually due to genetics and aging. Plucking the hair doesn't change the melanin production in *other* follicles.
* Plucking can damage the follicle: In fact, excessive plucking can sometimes damage the follicle, potentially leading to it not growing hair at all.
The reason people might believe the myth is that as we age, more and more hairs are naturally turning grey, so it might seem like plucking one causes others to appear.