I'm 5'3" and always considered myself average. The linked article talks about how more height on a man helps him get the promotion or the girl... but those things are not just "functioning normally", they are competitions, in which someone else will lose out if you gain an edge.
http://www.prguitarman.com/index.php?id=348
Nineteen seems to be an awful young cutoff age. There are plenty of high school students who are 19 in the spring.