[joshink1]

Thanks for that info.

A quick aside:

I'm curious why it's gene vs environment (either/or), and not gene + environment (emergent)? If the latter, then I'd think heritability would necessarily factor both genes and environment -- as genes don't express in a vacuum.

For example, the heritability of "general skin cancer risk" is both genetic (melanin) and environmental (latitude, sun irradiance...). Due to differences in UV exposure, the genetic influence is probably greater at lower latitudes than higher.