Things You've Always Wondered About Twins

Are you fascinated by twins? They've been the subject of myth and mystery and a source of curiosity to many. Even those who know twins or have them in the family may have some questions about them. You may have given some thought to what causes twins or why they happen, but did you ever wonder if some of the rumors are true. Do they have their own language that only they understand? Are they always exactly alike? Explore the mysteries of these things that you've always wondered about twins but didn't know to ask. 


Do Twins Have the Same Fingerprints?

Identical twin baby girls

Rebecca Emery / Photodisc / Getty Images

Twins have a lot in common. They usually share a birthday and identical twins even share the same DNA. But what about fingerprints? Are they alike even down to this finest of physical details?


Can a Boy and a Girl Be Identical Twins?

Boy and girl twins
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Twins and parent of twins face the question on a regular basis. "Are they/you identical or fraternal?" The general public doesn't really understand exactly what the terms mean; if they did, they probably wouldn't even pose the question. There's a short answer and a long answer to this question of whether a boy and a girl can be identical twins. The short answer is NO! However, the long answer, which involves very rare circumstances that most people will never encounter, means that there are always exceptions.


Can Twins Read Each Other's Minds?

Twins holding hands
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It's true that many multiples share a special connection that goes beyond that of ordinary siblings. Sometimes they will say or do the same thing at the same time. Some twins relate incredible stories of coincidence, where they think the same thoughts or sense each other's feelings. But while the twin bond is a special aspect of their unique relationship, is it really endowed with extraordinary supernatural qualities?


Can There Be a Hidden Twin?

Twin ultrasound picture seven weeks

Pamela Prindle Fierro

In times past, twins were often a surprise to their parents. Instead of one baby, two arrived! But now that ultrasound allows a sneak peek into the womb, few families are caught unaware in the delivery room anymore.

Despite the clarity of modern technology, multiples still manage to pull a few surprises and remain hidden from view during a portion of pregnancy.

Readers email me every day, suspecting that they are having twins, even though an ultrasound image only shows one baby. Are they right? Find out whether there can be a hidden twin pregnancy, even after an ultrasound. ​


Do Twins Have Their Own Language?

Twins whispering

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When my twins were toddlers, I'd observe them passing toys back and forth. As they'd accept the toy from the other, they'd respond "Aachee." Eventually, my husband and I adopted the term, and it became a family way of saying, "Thank you." Was it an example of twin talk? Or just baby babble? Find out the facts about "twin talk," and decide for yourself whether twins have their own language.


If Identical Twins Have the Same DNA, Why Aren't They Exactly Alike?

Twins sitting on chairs, wearing different styles
James Woodson / Getty Images

Anyone who knows a set of identical twins knows that they are alike in many ways, but also very unique individuals. Why is that? 

Identical twins form from a single egg/sperm combination and share the same genes. While they often look very similar and have the same tastes and interests, they're also very different.

Find out why identical twins are different, and how twin research is giving scientists important insight into human genetics


Can Twins Have Different Birthdays?

Twins celebrating birthday with cake
Getty Images / Photodisc

Twins, by definition, are two offspring born together, right? Yet, some twins blow out their candles on different days. Sometimes they celebrate their birthdays weeks or months apart, and in some cases, in different years!


Do Twins Run in Families?

Two sets of twins
Jessica Holden Photography / Getty Images

Everyone knows someone who is a twin or has a twin. And there's a general assumption that twins run in families. Some families do seem to have clusters of multiples in their family tree. Is it coincidence? Or a genetic trait?


Are Irish Twins Really Twins?

"Irish twins"
Moment / Getty Images

Are Irish twins really twins? Well, no. On the surface, the clear answer is “no”. Technically, the answer is "no." But the reality of the answer is, “Well, they could be.” or “So close, they might as well be.”


Can Twins Have Different Fathers?

Twin babies in diapers
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By definition, twins have the same mother. But, have you ever wondered if twins could have different fathers? Don't tell me you're not curious about this!


Do Twins Skip a Generation?

Twins riding on parents' shoulders

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I often hear the claim that twins skip a generation. What does that mean? That if you are a twin, you won't have twins? If you've ever wondered whether this is true, find out the facts.


What Causes Identical Twinning?

Twin bouys in yellow shirts
Tim Kitchen / The Image Bank / Getty Images

There are many known factors that increase the chances of fraternal multiples.

Over the years, as the multiple birth rate has risen dramatically, the increase has been attributed to many reasons, including fertility treatments, hormones in dairy products, and mothers who delay childbearing until they are older. Yet, the rate of identical twinning has remained steady, about 3 in 1,000 births.

Identical—or monozygotic—twins form when a single zygote (egg/sperm combination) splits into two. Why would it do that?

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