Genetics has probably only 55 percent to do with it. Look at Yao Ming his dad is 6'2'' his mom is 5'5'' he's frigin 7'6'' if i recall a recent TNT analyst saying so.

Ur spine is compressed every second because of gravity. u want to decompress it by lying down or hanging from a pole. Stretching does this.

TEST: Measure urself, do it in the morning then measure urself right b4 u go to bed I guarantee u will be taller in the morning than the night.