View Full Version : Identical Twins Separated At Birth: Nature vs Nurture

11-15-2003, 08:29 PM
Leslie Stahl right now on CBS 48 Hours...

11-15-2003, 08:29 PM
As in, separated to live with different people?

Watching football, will not change channels. :D

11-15-2003, 08:36 PM
Saturday: Twist Of Fate (http://www.cbsnews.com/stories/2003/11/04/48hours/main581771.shtml)Adriana never knew she had an identical twin sister, Tamara. What amazing twist of fate could bring them together after 20 years? These studies prove that it's nature over nurture by far! I love it!

11-15-2003, 08:37 PM
It doesn't prove anything. I think most people agree that it's a combination of genetic predisposition and environment that makes us who we are.

11-15-2003, 08:38 PM
Nope, these studies are facts that can'r be brushed off. Sucks to have PROOF that disagrees with your opinion, eh?

11-15-2003, 08:41 PM
What makes us who we are is far too complicated for it to be black and white.

Carry on.

11-15-2003, 08:44 PM
Originally posted by: Ornery
Nope, these studies are facts that can'r be brushed off. Sucks to have PROOF that disagrees with your opinion, eh?

What are you talking about? The article says :

""To the extent that identical twins are more alike in these things, we can say with a fairly strong degree of confidence that yes, genes do play a role," says Segal.

So, does it really matter what you do as a parent? Long-range studies of identical twins show that parenting is important because it affects how well your child will develop their genetic potential.

?We find that genes play a 50 percent role in fashioning personality, which means that half is also fashioned by the environment,? says Segal.

?The twins show some very striking similarities in personality, but when you look at personality development across a broader spectrum of people, you will find some differences.? "

11-15-2003, 08:44 PM
Well, here's a small excerpt from one of my books about twin studies looking at whether or not there were specific genes linked to masculinity and femininity.

Mitchell et al. examined 38 monozygotic and 32 dizygotic twins. Indirectly supporting the idea of nature over nurture, they found that there was a greater correspondence in self-reports of masculinity and femininity between identical twins than fraternal twins. They concluded that genes explained from 20% to 48% of the differences. But, they also concluded that environment explained from 52% to 80% of the differences.

I think that if you do a little research, you'll find that most reasonable scientists agree that it is an interaction between genetic predispositions and the environment that make us what we are.

11-15-2003, 08:45 PM
Sorry, we're all predestined it seems. Facts (http://www.modcult.brown.edu/students/angell/twinstudy.html). Bury your head in the sand, or keep reading... (http://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&safe=off&q=%22twins+separated+at+birth%22+study&btnG=Google+Search)

11-15-2003, 08:46 PM
studies only factualize the study, not the universal

11-15-2003, 08:49 PM
Well, as a good scientist, you're supposed to keep an open mind about alternative explanations, especially considering that biological explanations have never been very good at explaining all human behavior. I never said that genetics didn't play a role, just that there was an interaction and that most reasonable people agree with this theory as it better explains a continuum of human behavior and development.

11-15-2003, 08:54 PM
Twin Studies Corroborate Inherited-Behavior Theory (http://chiroman.com/twins.htm)Consider Jim Lewis and Jim Springer, [twins] separated at birth and brought together at age forty. Both had taken law enforcement training. Both had blueprinting, drafting, and carpentry as hobbies. Lewis had been married three times, Springer twice. Both first wives were named Linda; both second wives, Betty. Each named his first son James Allan. Each had a dog named Toy. More on these twins (http://matsonconsulting.com/cogsci/discussion/detail.asp?action=message&message_id=87)

11-15-2003, 08:57 PM
But that also says

"Accumulating scientific evidence suggests we are not solely our own creations: Our genetic inheritance plays at least as large a role in determining our personalities as the way we were raised or the education we received. Biology may not be destiny, but it contributes to it more than we may like to think. . . ."

I don't think anyone is denying that genetics doesn't have any impact on personality - I sure wouldn't and I'm an identical twin.

11-15-2003, 09:03 PM
Two sisters met after 35 years and they were wearing the same dress! More and more evidence piles up on the side of biological influence (http://www.enneagramcentral.com/study/een_e11.htm)

Identical twins raised together can't prove anything. It's the ones raised apart, yet living identical life styles, that tell the story.

Nature v. Nurture and the 'Twin Studies' (http://www.astrology.co.uk/geneticfate.htm)If identical DNA equalled an identical disposition, the implications for astrologers or environmental determinists are huge. Environmental determinists argue that environment and experience are decisive influences in determining human nature. This 'nurture' camp has been unsettled in recent years with studies showing that twins separated at birth and growing up in different environments live parallel lives - even from choice of clothes to partners to the timing of key events. Extraordinarily, studies suggested that the lives of separated twins tended to have a closer resemblance than twins brought up together.

11-15-2003, 09:11 PM
You haven't shown anything that says that environment has no impact on personality...even these 'studies' you link to do not say that environment has no impact. Who here is denying that genetics has no impact on our personalities?

11-15-2003, 09:12 PM
link (http://www.public.iastate.edu/~fulker/natureandnurture.html)

"In examining the evidence surrounding these ideas, one is as likely to see arguments that establish a continuum theory, one where both factors contribute to some degree, as to see an argument that works to establish a separatist view."

"Rather than a collection of isolated factors, heredity, the environment, and early social groupings all affect one another."

Let's face it, you're the one that clearly is unwilling to look at the other side of the argument. Most scientists will agree that there is no definitive answer. There is intriguing research that suggests genetics plays a large part. There is also intriguing research that suggests the environment. There is an interaction between the social and the biological. It doesn't matter what genes you have, if you do not have access to the same levels of education, role models, etc, you will not live up to your full potential.

For every article you link there exists an article that will argue the opposite. There are no definitive answers.

11-15-2003, 09:30 PM
"You haven't shown anything that says that environment has no impact on personality...even these 'studies' you link to do not say that environment has no impact. "

What a coincidence... neither did I!

"There is intriguing research that suggests genetics plays a large part..."

The results of these studies are undeniable. If it weren't for these twins, all we would have is theory and opinions. Nobody wants to admit how HUGE the biological factor is. Is it like a priest discovering there is no God, or what? ;)

11-16-2003, 09:42 AM
Nature vs. Nurture (http://www.try.org/newsletter/1997fall2.shtml)...As it happens, though, some of the most subtle and complex aspects of personality - traits that one would assume could only be shaped by environment - turned up with surprising frequency among identical twins raised apart. These characteristics were measured in 11 independent personality scales. They reflected such diverse qualities as "social potency," the ability to take charge in group situations; "achievement," the desire to be successful at work; "well-being," the capacity to experience joy and excitement; "self-control," the lack of impulsiveness; "harm avoidance," the propensity to steer clear of destructive situations; even "traditionalism," the tendency toward conservative moral values...

...This was borne out in the Minnesota study, in which, again and again, identical twins with very different schooling emerged only a few IQ points apart. In a telling example from Britian, a twin was adopted by a wealthy lawyer and attended exclusive private schools; her sister grew up in a lower middle-class section of East London and quit school at 16 to work. Despite their opposite paths, their IQ scores were only a point apart...

11-16-2003, 11:44 AM
Here's an interesting coincidence. A family moved in our neighborhood about 15 years ago. The father married a woman who had two boys from a previous marriage. They were 5 or 6 years old when they moved in. The older boy was a bit effeminate, but a really nice kid. His younger brother had quite an attitude, and was prone to getting in trouble. They moved out in 1991, when they were 8 or 9 years old.

We just saw the mother, father and younger son at a wedding the other day. My wife decided to look up records from our courthouse, and found that their real father had been convicted of grand theft forgery in 1990. Farther down the list of cases, the older son was recently sentenced for burglary! We figure it's just a matter of time before the younger one is added to the list, despite living with a very good step-father and mother. It is, after all, in his blood... ;)

11-16-2003, 11:47 AM
Didn't the Olsen twins make a movie that was essentially the same thing?

11-16-2003, 11:51 AM
Me and Emily are fraternal,not identical. (http://www.kidzstuff.org/ashleym/)

They don't count. :P