[jacobolus]

You’re misunderstanding “heritability”. http://en.wikipedia.org/wiki/Heritability http://en.wikipedia.org/wiki/Twin_study#Methods

The study in question: http://www.ncbi.nlm.nih.gov/pubmed/17564516

PDF: http://psychology.uchicago.edu/people/faculty/cacioppo/jtcre...

[xxchan]

I see, obviously the math is a bit more involved. I assumed those 8000 were identical twins who were separated at birth. Thank you