My immediate family's short on both sides. I have a tall cousin (6' 2") and three tall uncles (somewhere in the 6' vicinity) but in this household I'm the tallest, although I only overtook my father in the last month or so.
That being said, I was one of the shortest people in my class at school for many years. I was average height until about Year 3. I considered 5'6" in Year 11 to be a major accomplishment.
My brother's only sevenish at the moment, but he will be taller than me in time, I am sure.
Ah well.