Height is an inherited trait. If you have tall ancestors you will be tall and vice versa. Do not worry if you are tall and both your parents are short. No,you are not adopted! It’s likely that their parents or grandparents were tall. Therefore they both carry “tall” genes. Since you inherit half of your genes from your mother and half from your father, you can end up with 2 “tall” genes and grow very tall, even taller than your parents, or 2 “short” genes or 1 “tall” and one “short” gene giving you medium height.