Question

Why do tall parents have short children and vice versa?

Answer 1

Where is this trend followed it is not necessary dude and tall parents in most of the cases have tall children and vica versa.
hope it helps you out

Answer 2

A child whose parents are both 6' is likely to be the tallest kid in kindergarten. If both parents are unusually short, their children probably will be short too. But even kids who have average-height or tall parents may inexplicably stop growing -- a condition known as idiopathic short stature (ISS).