Evil Twin Syndrome?

Factual Questions
1

I call it evil twin syndrome. But I am sure there’s a more technical term for it. Post one if you know it:).

Identical twins just sometimes seem to be polar opposites of each other. And yet they have almost identical DNA.

I’ll tell some of the ways just I have noticed it. Back when I was still in high school, there were these two identical twins, Sherry and Shelly.

Sherry was sweet and kind and compassionate and nurturing. Shelly was a bitch. How else can I put it?

Whenever they were together, even their expressions were different. Sherry had a warm, trusting smile. Shelly always had a sarcastic expression on her face.

I have noticed it for other twins too, outside of my high school experience. Media stories on twins always confirm what I am saying (I.e., that they are polar opposites). Heck, I even sometimes see pictures of identical twins. And, yes, their expressions always are quite different.

My question is simply, what do you call this coincidence? And what is the cause?

I guess I can let you all in a little secret, what I deduced was the reason for it, when I was still in hs. I concluded it was caused by a subconscious loathing of the fact that they might be viewed as, well, ‘identical’. I will trust, though, you can all come up with a better explanation;).

Or maybe I am wrong, there is no such syndrome. But as I said, whenever the media does a story on identical twins, the story invariably focuses on how they contrast with each other.

Thank you in advance for all your replies:)

2

There was a set of identical twins in my school when I grew up and their personalities were fairly similar. They acted enough alike that you had to be around them for a while to pick up on the subtle differences in their features to know which was which without asking them.

Some twins embrace their nearly identical nature. Others rebel against it and intentionally try to be as different from each other as possible. Your personal experience is probably weighted towards the latter, and the media stories you’ve seen are probably focused on what makes a good read instead of what the reality of the situation is. These don’t match the findings from actual twin studies.

From here: Inheriting Personality Traits | 16Personalities

3

If they truly are identical twins, their DNA is exactly identical.

But it’s possible for two fraternal twins to look so much alike that they are mistaken for identical ones; it happens to siblings who aren’t twins too. Perhaps some of those so different identical twins are fraternals.

4

Even identical twins will have slight differences in DNA, from mutations and the like.

Jim B., I knew a pair of identical twins like that, too, with the same personalities that you describe. In their case, though, it wouldn’t have been an unconscious decision to want to be different: They consciously decided to differentiate between each other (for instance, by wearing different hairstyles). Now, the personality differences probably weren’t conscious (it’s tough to choose a personality), but it’s probably another facet of the same thing.

5

I was close friends with a pair of identical twin boys in high school. They both had similar interests, such as sports, but they couldn’t have been more different in terms of their personality. Neither of them was “evil” in any sense of the word, but one was more serious about life than the other. They usually combed their hair slightly differently so it was fairly easy for me to tell them apart, even though they looked identical at first glance. Given that they each had experienced life differently it’s not surprising that they have different personalities. I don’t think who we are is solely determined by our genes, so it doesn’t surprise me that they weren’t carbon copies of each other. If I remember correctly, one did better in school than the other. Again, I don’t think that’s all that surprising really.

6

We’re not determined solely by our genes, no, but a lot of the other things that determine who we are are also shared between (typical) twins.

7

I have relatives who are identical twins - fairly similar personalities, sense of humor, etc. except - one is straight and one is gay.

8

Wouldn’t that require the mutations to take place after the original ball of cells separated, but before there were enough cells for the mutations to be ‘local’ (for lack of a better word)? It can happen but I’m not clear on the “will”; will seems a bit strong.

9

The one the left is the sinister twin.

10

Epigenetics, I think it’s called? Otherwise, as an identical twin, I have to say I favor Chronos’ reading: we sort of used each other as a foil in order to try to develop some clearly differentiated personality/identity for others. The only thing lamer than being known as the bitch is not being recognized as an individual at all.

11

Mr.Wrekkers dad was an identical twin, they were very different. I always assumed it was their adult life choices that did this. One went the Military the otherwent right into employment after highschool. One had kids the other didn’t. They stayed very close til they died. And, they died within a month of each other. That was intriguing to me.