> 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?
> 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.
Hmm, this could be right to some extent, but (apart from what goes
into the 0.02) it seems to imply
(1) that there are no factors that are generally good, such as good
nourishment, loving parents, lots of intellectual stimulation,
enriched environment etc. People who belive upbringing makes a lot
great difference would have difficult time trying to swallow the fact
that these factors don't make any significant net improvement.
and
(2) If some of these factors do a lot of good for some
genotypes, then they must do positive harm to many other genotypes.
This would also be hard to accept.
Nicholas Bostrom
London School of Economics
Department of Philosphy, Logic and Scientifc Method
email: n.bostrom@lse.ac.uk
homepage: http://www.hedweb.com/nickb