Sex And Ethics

On the surface, "Eastern" people are conservative and not very open about sex. "Western" people are open-minded and liberal about sex. How does this correlate to the birth rate and population? Clearly, people who are "conservative" like sex more. They have more babies. Perhaps it is just more exciting to do stuff in secret, knowing well and good that it's just horribly taboo. I guess it excites some people. It obviously excited those Easterners enough for them to reproduce like rabbits.