How to Tell Your Identical Twins Apart

Identical twin baby boys facing opposite directions with their heads together
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Many expectant parents of twins may worry about how they will tell their twins apart. They might be concerned that they will mix up the babies and won’t know who is who. Sleep deprivation and the chaotic demands of caring for multiple infants only exacerbate the fear.

Parents of multiples have many worries before their babies arrive—how to care for both babies at the same time, how to get enough sleep, how to pay for everything. Fortunately telling twins apart is one fear that can be taken off the list.

Most parents find that mixing up their babies is the least of their concerns. After only a few hours or days at most, they are distinguishable as individuals. Even if they look alike, parents just know the difference.

Perhaps that is why this fear resonates with some parents. Recognizing and knowing your child is a deep-rooted, primal instinct. To not recognize your child, even if the form of temporary amnesia like mixing up twins, would be to admit failure at that basic parenting trait.

Similarities of Twins

For families of dizygotic (fraternal) twins the worry is generally not an issue. Dizygotic twins develop from two separate egg/sperm combinations and are no more similar than any two siblings born at separate times.

However, don’t discount the strength of family resemblance. Fraternal twins can still look very similar, just as siblings can. With distinctive features—eye color, hair color, facial features, body size, or head shape—fraternal twins are usually pretty easy to tell apart. For boy/girl twins, that only requires a quick check of the diaper area to confirm.

On the other hand, monozygotic twins aren’t called identical twins without reason. Forming from a single zygote (sperm/egg combination) that splits into two, the two individuals share the same genetic makeup. They can have remarkably similar physical characteristics.

A person’s identity is more than just what they look like. Personality, expression, communication, emotions—all of these traits vary among individuals.

And while DNA controls many characteristics, even monozygotic multiples that look exactly alike are unique individuals who will quickly differentiate themselves to their parents. As they become familiar with their infants, parents will quickly grow to recognize and appreciate each child’s unique imprint. Likewise, those that know and love the multiples will learn to distinguish them as well.

However, mistakes do happen. It is true that exhaustion characterizes the first year of parenting twins, and being overtired can certainly cloud judgment. It is important that you keep track of who is who, especially if you are administering medications, monitoring feedings, or tracking developmental milestones.

If you are an expectant parent of twins and are worried about telling them apart, there are some steps you can take to prevent a mix-up. Employing these strategies will ensure that mixing up your twins results merely in hilarious hijinks and not any serious consequences.

Physical Differences

Even identical twins have some physical characteristics that aren’t exactly alike. In fact, there are rare perinatal circumstances that can produce identical twins who don’t really look alike at all. Twins with twin-to-twin transfusion syndrome (TTTS), for example, may result in a size disparity.

Labor and delivery may produce infants with different head shapes. And even identical twins have differences in their epigenome, chemical modifications within a person’s genetic material. Birthmarks, moles, and freckles also differ among individuals.

As you get to know your twins, you’ll identify physical clues that will help you distinguish between them.

Mirror image twins have reverse asymmetric features, almost like two individuals looking in a mirror. For example, they may have a hair whorl or cowlick that swirls in opposite directions. They may have birthmarks on opposite sides of their body.

Minor physical characteristics such as these can serve as clues to help tell individuals apart. Once you have determined a distinguishing physical feature, you can utilize it when trying to tell your twins apart. When others inquire how you do it, you can let them in on the secret.

Planning a Clue

Some parents utilize color coding. They consistently dress each twin in a designated color. For boy/girl twins, the color combination of choice may be blue/pink; for two girls, perhaps purple and pink, and for two boys, blue and green. You can have fun with it.

One parent of boy twins named Nick and Patrick used red and green. Nick wears red for St. Nick and Patrick wears green for St. Patrick. This system is invaluable for helping others tell twins apart, especially in daycare or school situations. It is also helpful to use a color coding system when you take photographs of your twins. Looking back, you'll always know who is who.

The problem with color-coded clothing is that the system can be burdensome to maintain.

It requires parents to shop more carefully and only purchase items that meet the color code. It also requires diligence in keeping up with laundry so that everyone has access to wardrobe options in their color.

If color-coded clothing is too complicated, try some other quick color clue. Some parents paint a toenail with nail polish as an identifier while others use hospital bracelets or jewelry. Just be sure that any accessories you use are safe for babies or children, with nontoxic materials or small parts that could present a choking hazard.

7 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Pamela Prindle Fierro
 Pamela Prindle Fierro is the author of several parenting books and the mother of twin girls.