How many times have you heard the terms “mirror twins” and “identical twins?” People usually assume all twins are the same. There are several examples of mirror twins in Hollywood such as Rami Malek and Sami Malek, Scarlett Johansson and Hunter Johansson, Linda Hamilton and Leslie Hamilton, and the list goes on.
Some twins are identical, some are not, and then there’s the pair that is identical but are a different sex. Confused? Well, we are here to clear the confusion once and for all. Before we proceed, let’s talk about the few common twin pairs that we usually come across:
- Identical Twins (twins with almost similar features)
- Fraternal Twins (twins with different or same sex but completely different features)
- Mirror Image Twins (not really a category of twins but a term used describe the features of twins, which are almost unrecognizable)
Now that you know the basics, have a look at a few frequently asked questions about mirror image twins:
Can Mirror Twins Be Different Genders?
If you have a twin, do people often come up to you and ask, “Are you identical or fraternal twins?” If you are a girl and your twin is a boy, then the answer is clear, but if both of you are either males or females, then one automatically assumes that you two are identical.
In order to understand how mirror twins are formed, you need to know about zygosity. This term explains how a zygote is formed with the union of a male gamete (germ cell) and a female gamete during the process of sexual reproduction. In simpler terms — zygosity describes the origin of the twins.
This is where they are wrong! Keeping in mind the combination of zygotes, mirror twins can only be identical, as in boy-boy or girl-girl. This is because they are monozygotic.
Can Mirror Twins Be Identical?
It seems that most of the questions surround this one dilemma. As explained earlier, the extent of similarities depend on the zygote. Since we are talking about identical twins, which always have the same sex, then the answer is a little complicated.
Not to confuse you, but the answer to this question is yes and no. We have already established that identical twins are monozygotic. The reason why identical twins are also called mirror twins is because they are a reflection of each other. This is where the similarities end. If you look closely, you will find small differences in their physical characteristics, which include:
- Eye shape
- Eyebrow shape
- Ear shape
- Nostril shape
- Hair whorls
These physical characteristic might be on the right side of one twin and on the left on the other twin. This is perhaps one of the top features that differentiate mirror twins from one another.
What Causes Mirror Image Twins?
Think of mirror twins as nature’s copy-paste. This doesn’t mean that there’s no scientific backing behind their formation. Between the 4th and 8th day of a normal fertilization process, 1 fertilized egg splits into 2 identical embryos. These two embryos form into two babies.
However, in the case of mirror twins, the egg splits between the 9th and 12th days, which cause the similarities. Since the fertilized egg was divided, the embryos develop similar features
How Are Mirror Twins Formed?
Going into more detail, the formation of twins is quite different. 1 egg is fertilized by 1 sperm and as a result, a single zygote forms. The pregnancy proceeds naturally with the embryo growing for 2 weeks after conception. Then, the embryo splits and forms two identical parts. Now, the womb has two embryos and the twins have the same sex, and 100% of their genes match. There are only 25% chances that identical twins turn out to be mirror twins.
How Many Mirror Twins Are There in the World?
There’s no information available online on how many twins are there in the world. However, it is estimated that out of every 1,000 people, 32 are twins. It’s not known whether this estimated population comes out as mirror twins or fraternal twins.
Are Mirror Twins the Same as Identical Twins?
This is the one question that confuses people whenever the topic about twins is brought up. As explained earlier, mirror twins is a term given to the characteristics that describe identical twins. Identical twins are monozygotic, so when it comes to differentiating mirror twins, you will have to look for the subtle changes in them. For example, one twin might be left-handed and the other right-handed.
Identical twins are born when the egg splits between the 2nd and 8th day, whereas mirror twins are born when the egg splits between 9th and 12th day. Identical twins will have a few visible physical differences but mirror twins are carbon copies of themselves. In some case, mirror twins are also mentally connected in way that if one has a headache, the other experiences it too.
When the egg splits after the 12th day, the twins born are called conjoined twins. These types of twins are bonded to each other physically. They might share a limb or a vital organ.
In a nutshell — yes, mirror twins and identical twins are the same.You can also say that all identical twins are not born mirror twins, but all mirror twins are known as identical twins.
Are Mirror Twins Organs Reversed?
Yes, but not the vitals ones. The spleen in one twin might be on the opposite side and vice versa. However, when it comes to the heart, the appendix and other such vital organs, the mirroring is quite rare.
Are the Property Brothers Mirror Twins?
A little background — The Property Brothers is a Canadian TV show in which two brothers Drew Scott and Jonathan Scott who are identical twins buy neglected houses and then renovate them.
Fun Fact: Jonathan was the first to be born and as the doctor was finishing up, he realizes that there was another baby. To the mother, this was a complete surprise because she wasn’t expecting twins.
Most people consider the Scott brothers to be fraternal twins because they look quite different. Even their mom had a hard time coming to terms that they are identical and fraternal. Fans can easily set them apart because their physical features are different. As we have learned, mirror twins tend to be mirror images of themselves, which is why we can safely say that the Scott brothers are not mirror twins.
Are the Olsen Twins Mirror Twins?
We all know the Olsen twins from the hit TV sitcom Full House. It was one of the top-rated shows in the late 1980s. Most of the audience watching the show sitting at home had no idea that Michelle had a twin. It wasn’t until the episode where we see two Michelle; we realized there’s a possibility that this was no video graphic manipulation.
Yes, the Olsen twins look exactly the same but they are not mirror twins. In an interview, the Olsen twins revealed that a doctor told them they were sororal twins (fraternal twins with same sex). They definitely have different physical characteristic such as Mary Kate is taller than Ashley and Ashley is right-handed, whereas Mary Kate is left-handed.
Is There Any Relation Between Mirror Twins and Left Handedness?
Studies have been conducted in depth on twins to find out how their brain development affects their activities. There has been a long standing debate on whetherthere’s any relation between mirror twins and their hand preference. To make it clear for you, most of the twins are left handed.
In fact, according to Washington State Twin Registry, in about 21% of monozygotic twins, one twin in a pair is left handed and the other is right handed. If we talk about the general population, only 10% of the people are left handed. However, when it comes to twins, about 17% of them are left handed.
The left hand preference is not due to any genetic changes. A study published in the Frontiers of Psychology journal conducted a study on twins to find out their hand preference and cognitive differences. The researchers weren’t able to come to a conclusion due to lack of research data, especially because of zygotic discernibility. However, the results did reveal that most mirror twins prefer their left hand. They chalked up the weak results to fewer participants.
Environmental factors might have a hand in the hand preference, which include rising hormone levels in the mother, stress during birth and position of the twins in the womb. If the twins born are mirror twins, then there’s a high chance that one of them will be left handed. Researchers weren’t even able to determine the preference of left hand in a study that had 4,000 twin participants. This brings us to the conclusion that it’s not the sample, the environment or genetics that cause this phenomenon but a combination of these three and something else.
What we have learned here is that mirror twins are actually identical twins but the same cannot be said when the positions are reversed. People might look exactly alike and not be mirror twins, as is the case of Olsen twins.Mirror twins might be the mirror image of each other but they don’t have the same fingerprint. Only genetics can determine what kind of twins a pair is and nothing else.