Conversation so far:
what is the average height of a male human
According to the Centers for Disease Control and Prevention, the average age adjusted height for American men 20 years old and up is about 5 feet 9 inches tall.
what is the average height of a female human
The average height of women varies around the world. In the U.S., the average woman is around 5 feet 4 inches
which country has the tallest population
The Netherlands comes in first for height with its citizens' average heights at 6.03 feet across both genders.

Question: what is the main factor
Self-contained rewrite: what is the main factor that determines height