I'd suggest this: The genetic stuff determines your predisposition to react
in certain ways to certain stimuli. So adopted children reared together react
in totally different ways, being genetically unrelated. Twins reared apart
tend to encounter some of the same stimuli naturally.
So, same upbringing vs. different upbringing, for the genetically unrelated,
makes no difference in intelligence; they react in different ways. But, given
the same genetic material, you start to notice differences in upbringing.
In other words, what this data tells us is that upbringing, although a major
factor, has effects which are almost totally dependent on genetic
predispositions. You therefore cannot compare two styles of upbringing,
except for a particular genetic base.
-- sentience@pobox.com Eliezer S. Yudkowsky http://tezcat.com/~eliezer/singularity.html http://tezcat.com/~eliezer/algernon.html Disclaimer: Unless otherwise specified, I'm not telling you everything I think I know.