My brother is over six feet tall. We are of Dutch descent and the Dutch are frequently very tall. 
Oh I didnt know that Dutch people tend to be tall interesing
Yes, Dutch people are tall, though height can serve as indicator of health and good nutrition. 
on average how much taller are they then US males do you know
It depends, height increases with a populations' genetic profile. 
interesting, is there a specific reason, I guess just genetics
NOt really, but within a population, height is often shared characteristic,. 
all people or just men, women too?