Ok, so I wanted to bring clarity to this much discussed statistic. A lot of people say "The Younger generation is getting taller". This is true, but the amount is negligible.

Avg US height is 5' 9.5" and avg 20-29 year old height is 177.6 CM (5' 10"). Avg white US male (20- 29 years old) is 5' 10.5"

Check this page, and open up the reference 152 for a detailed pdf with the height statistics in the US.

My theory for the slight increase in younger generation height is improved nutrition and higher frequency of having children for tall people than short people.

http://en.m.wikipedia.org/wiki/Human_height