Curious about Identical Twins? 8 Facts & Myths

As many of you know (unless you’re new here, in which case, nice to meet you!) Tamara and I (Terry) are identical twins. And being identical twins, we have gotten our fair share of questions and assumptions about twinhood over the years. 

There’s a lot of confusion about identical twins, what it actually means, and what’s the experience of living with someone who looks exactly like you!? While there’s a lot of information out there, it’s hard to tell twin facts from fiction. While some common twin myths do have some truth to them, others are entirely false. 

Today, we thought we’d take the chance here to identify common assumptions we get as identical twins, and if there’s any truth behind them. 

True or False?

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1. Identical twins always get Multiple Sclerosis (MS) (or another chronic illness) if one of them is diagnosed


Yes, we both are living with Multiple Sclerosis (MS), but that isn’t always the case. There are plenty of twins out there that have not both been diagnosed with chronic illness. Actually, it MORE likely that only one twin will develop the illness.  

You may be asking, “But Tamra and Terry, MS is a genetic condition – right? Since your genetic makeup is the same, wouldn’t you both get the illness?”

Well, yes. That would be true if MS was completely genetic. Continuous studies are being done are the causes of MS. But right now, genes that have been studied have only been shown to increase the likelihood to a small degree. 

According to an Australian study in 2013, Identical twins have a 1 in 5 chance of both getting diagnosed with MS. 

2. Twins have the same DNA 

True – sometimes. 

This one is all about the difference between fraternal and identical twins. Can you guess which one shares the same DNA?

Yes! It’s identical twins. 

What makes twins identical isn’t necessarily how they look – it’s how they form in development. Identical twins come from the same egg, making their genetic makeup the same, while fraternal twins share half of their genes since they form from different eggs. 


Identical twins are always the same gender, and only fraternal twins can be different genders.

3. Having identical twins is genetic 


“I’m an identical twin and I have 2 brothers that are twins. Is our son having twins because of our background? Does it have to do with our genetics?”

-90% of curious identical twins

This is a question we get asked quite a bunch! However, there is no genetic component to the conception of identical twins. This is considered more of a fluke than caused by any genes in particular. So for me and Tamara, we aren’t any more likely to have identical twins than my non-twin husband. 

Now, if we were talking about fraternal twins, that would be a different story!

There is some genetic component to this, and they are actually 2.5 times more likely to have twins themselves.  

4. Identical twins share the same fingerprints


Common misconception, but identical twins DO NOT share the same fingerprints. Fingerprints are unique to the individual person and no two people have the same, even if their genes are the same. 

However, there may be some similarities between the fingerprints of identical twins. According to Washington State, the loops and ridges of fingerprints could be very similar. 

Maybe it’s time for us to check out our fingerprints to see how similar they really are.  

5. Identical twins read each other’s minds 


This is a tricky one because personal experiences and science don’t always add up. But me and Tamara can definitely attest to some element of truth in this based on our experiences. 

When we were little,  we actually had our own language which our parents could not understand. It was like we had our own secret code! 

There were some downsides though – as it created a speech impediment in us as children. 

There was also other cool stuff we could do which showed us first-hand the powerful emotional connection between twins. When one of us was upset or had something weighing on our minds, the other could always tell – twin telepathy, if you will.  And when I was in the hospital at age 18, Tamara called our parents and realized I wasn’t getting the intensive care I needed. 

We’ve had a bunch of experiences like this over the years that we’ve heard similar stories from other identical twins time and time again. But there isn’t any scientific evidence right now that points to identical twins being able to read each other’s minds. 

So we’ll leave this one as a strong maybe. 

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6. Identical twins have the same personality


This identical twin myth is actually true – to an extent! That’s because the application of it really depends on whether or not the identical twins were raised in the same environment. 

For instance, countless studies have shown that identical twins are twice as likely to share personality traits as fraternal twins. 

But do similar traits mean identical twins will act the same? Not always. 

It comes down to the common nature/nurture debate of personality. While yes, nature and fact point to identical twins sharing personality traits, nurture affects what is seen. For example, if identical twins are raised in different environments but both are high on introversion, one may be raised in an environment where they are more encouraged to leave their comfort zone. 

If that’s the case, they may not show as many behaviors associated with introversion as twins raised by the same parents. 

The same is true for mannerisms – as they are impacted by both nature and nurture. 

As for me and Tamara, our personalities have developed a little differently even though we have similar traits and mannerisms. We use the same hand motions, same inflections in our voices when we speak, and have a very similar style in clothes and makeup. 

7. Parents always know when they are having identical twins 


Another myth we’ve heard is that the mother always has the knowledge of what type of twins she’s having

This may be more true today with the amazing advances of technology, but not when we were born! X-rays back then could only tell that the mother was having two babies, but not whether they were identical twins or not. So our mother actually had no idea if we were identical or fraternal twins, and neither did we. 

Actually,  for most of our lives, we didn’t even know if we were true identical twins. We always felt in our hearts that we were, but wanted to know for sure. A couple of years ago, we took a genetic test, and thankfully, matched as 100% identical. 

So although it’s more likely today, parents may not always be sure whether their babies are identical or fraternal!

8. Irish twins are true twins


Something we were asked often growing up is whether or not we were Irish twins and if Irish twins are true twins. 

Although this has the word “twin” in it – there’s a big difference between Irish and identical twins. 

Irish twins are those born within 12 months of each other, much unlike identical or fraternal twins. This term actually originated in the 1800s as a way to poke fun at Irish families who didn’t have access to birth control. 

However, that doesn’t mean that Irish twins aren’t sometimes treated like true twins. In fact, we had a lot of friends growing up that came to school dressed alike as Irish twins!

In Conclusion

There are plenty more myths about identical twins out there, and probably way more that’ll surface. But answers to these can give you an idea of the true definition of an identical twin!

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