
Siblings Share Genes, But Rarely Personalities - fogus
http://www.npr.org/2010/11/18/131424595/siblings-share-genes-but-rarely-personalities
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lmkg
Identical twins separated at birth tend to have more similar personalities
than identical twins who grew up together. The hypothesis is that, due to the
presence of each other when growing up, they actively (though subconsciously)
differentiate themselves. It's reasonable to assume the same effect would
happen to some extent with other siblings. The fact that twins (or siblings)
are more similar when raised in different environments would seem to
contradict the idea that subtly different environments are responsible for the
majority of sibling discrepancy.

I'm working on finding the citation. The phenomenon is known as "twinning" but
that apparently refers to a bunch of other junk that makes it hard to find
what I'm referring to. I may have to dig out my bioethics book when I get
home.

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sp332
I'd heard of this effect, and I'd always wondered how it affected more
homogenous populations. I wonder how much of the "freakyness" in Japanese
culture (I mean from an American perspective!) can be explained by individuals
trying to distinguish themselves from the thousands of very similar people
they live with.

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torotopo2
As one of three boys born within four years of each other, I support Theory
Three: Exaggeration. Yeah, we had differences, which were wildly exaggerated
and reinforced, and which pushed us into different universities and it all
goes to sh!te from there.

As the father of two now teen boys born within 12 months, they're freaking
aliens compared to each other -- except other people can't tell them apart.

It's not my fault.

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brfox
My two kids had a completely different personality when they were each 2
months old. Their personalities have hardly changed in 4 years. So, none of
these 3 theories account for this - I think genetics is a much bigger deal.

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radioactive21
My sister and I are completely opposites. I am an introvert, she is a crazy
extrovert. She is a crazy risk taker, while I am risk adverse.

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tincholio
Anyone interested in this stuff should read Steven Pinker's "The Blank
Slate"...

