Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!sri-spam!sri-unix!quintus!ok
From: ok@quintus.UUCP (Richard A. O'Keefe)
Newsgroups: comp.ai
Subject: Re: AIList V6 #86 - Philosophy
Message-ID: <997@cresswell.quintus.UUCP>
Date: 19 May 88 01:45:37 GMT
References: <1579@pt.cs.cmu.edu> <3200016@uiucdcsm> <523@wsccs.UUCP> <2865@cvl.umd.edu>
Organization: Quintus Computer Systems, Mountain View, CA
Lines: 32

In article <2865@cvl.umd.edu>, harwood@cvl.umd.edu (David Harwood) writes:
> In article <981@cresswell.quintus.UUCP> ok@quintus.UUCP (Richard A. O'Keefe) writes:
> >In article <523@wsccs.UUCP>, dharvey@wsccs.UUCP (David Harvey) writes:
> >> lives.  Even a casual perusal of the studies of identical twins
> >ONLY a casual perusal of the studies of separated twins will have this
> 
> 	Please, Mr. O'Keefe - please stick to programming languages
> where we very much appreciate your competence. But you really don't
> know what you are talking about concerning methodologies or results of
> twin studies. 

I am trained in Statistics.  I have not worked in psychology myself, but
I have spent many hours in conversation with statisticians who have, and
I have advised at a computing centre where psychologists brought their
work to be blessed by the computer.  There is no way I can pretend to be
an expert psychology or twin studies, but I am not wholly ignorant of
the literature.

> Moreover,
> it is a naive fallacy for you to assume that genetic expression is not
> dependent on enviroment. That is, the fact that separated identical
> twins might be selected because they are found in the same physical or
> cultural "niches" has to be allowed for theoretically alright, but 
> the issue is whether twins are comparatively more similar in various 
> more or less different enviroments.

Please don't put words in my mouth.  Of course genetic expression is
dependent on environment.  That was my point!  My point is that because
_both_ genotype and environment are strongly influential, and because
so-called separated twins usually have _very_ similar environments, the
results from "separated twin" studies are anything but uncontentious.
I do not mean to claim that such studies are BAD, my point is that a
non-superficial study will show that the results are not clear-cut.