Very, somewhere in the 80% range: "The estimated heritability was 0.79 (SE 0.09) for height and 0.40 (SE 0.09) for BMI, consistent with pedigree estimates." [0][1]
>For bonus points: why has the heritability of height changed over time
It hasn't.
>and varied by country?
It hasn't.
Love it when the bonus questions are easier than the main questions.