Re: Gene supremacy (Was: Re: Meme supremacy)

Eliezer S. Yudkowsky (
Thu, 14 Aug 1997 21:19:00 -0500

Nicholas Bostrom wrote:
> Anders Sandberg wrote:
> > Identical twins reared together 0.86
> > Identical twins reared apart 0.75
> > Nonidentical twins reared together 0.57
> > Siblings reared together 0.45
> > Siblings reared apart 0.21
> > Parent-Offspring reared by parent 0.36
> > Parent-Offspring not reared by parent 0.20
> > Adopting Parent-Offspring 0.19
> > Adopted children reared together 0.02
> >
> How do people who believe that upbringing accounts
> for much of the variability of intelligence explain the fact
> that the correlation coefficient between adopted children reared
> together is only 0.02?

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.

--       Eliezer S. Yudkowsky

Disclaimer:  Unless otherwise specified, I'm not telling you
everything I think I know.