They often look alike, talk the same and even laugh the same! Twins are a biological marvel and genetic miracle. There are many types of twins. They include identical, fraternal, mirror, conjoined, polar body or separated at birth. No matter which type they are, twins have many qualities which continue to fascinate us. Here are 10 facts about twins which will leave you in awe!
Identical twins aren’t identical
Many people know that identical twins actually have the same DNA. Despite this fact, they actually aren’t identical in every way. Some physical features of identical twins are different from each other. Examples of these are fingerprints and belly buttons. This is because their bodies change over time as they change. Even their natural body scent become different over time!
There are semi-identical twins
Identical twins occur when the fertilized egg splits in half. However, an egg can split before fertilization. In this case, each egg can be fertilized by different sperm. This results in semi-identical twins. These twins share 75% of their DNA material. They are not quite identical but they are much more similar than fraternal twins.
The mirror twins
If a fertilized egg splits 1 to 2 weeks after fertilization has occurred, this is known as late splitting. It normally results in mirror twins. These are twins who are essentially mirror images of each other. They form in the womb facing each other. As such, they are perfect opposites. One of the twins might be left-handed and the other right-handed. Their birthmarks may also be oppositely placed. The DNA of mirror twins is exactly the same. Therefore, they look very similar. The only way to tell mirror twins apart is by noticing their distinctive features early on.
Twins are being born more often now
In the 21st century, twins are becoming more and more common. Between the years of 1980 and 2003, the rate of twin births shot up by 75%. Initially, fertility dr*gs were thought to be the cause. However, Dr. Gary Steinman of the Long Island Jewish Medical Center indicated that cow’s milk was to blame. Women who drank it during their pregnancies increased their likelihood of getting twins! The milk contains the growth hormone IGF which stimulates women to produce 2 eggs at the same time.
Twins are more frequent in some areas than others
Generally, twin births around the world settle at 4 per every 1,000 births. Notably, fraternal twins can run in families. There are women who are genetically predisposed to hyper ovulation. Due to this fact, some regions of the world are famous for the high rates of twin births. In Benin, there are 27 sets of twins for every 1,000 births. It is the highest rate in the world. Scientists believe that the Yoruba people produce twin births due to their diet and genetic predisposition.
Twins’ mothers live for a much longer time
According to the Utah Population Database, women who gave birth to twins lived for a longer period of time than those who gave birth to singletons. The analyzed data spanned the period from the early 1800s to the 1970s. It led the scientists to a hypothesis that mothers who give birth to twins have genes which are naturally stronger resulting in longer life.
Social from the beginning
The scientific journal PLOS One indicates that twins normally begin to interact with each other at 14 weeks in the womb. They lean on each other for comfort, place their heads together and touch each other gently too. This helps them to develop a form of non-verbal communication. Furthermore, this form of interaction helps them to create the unique connection that twins share.
Twins develop verbal communication with each other before they can communicate with the world at large. Children generally learn how to speak by interacting with their caregivers. Twins have an advantage because they can interact with each other. Even if they mispronounce the words which they hear, twins can assign meaning to these mispronunciations. Over time, they create a secret language between them!
Low level of cognitive skills in the childhood stage
Twins can experience speaking challenges in early to mid-childhood. This is according to a study performed between 1950 and 1954 in Birmingham, United Kingdom. In Aberdeen, Scotland, a study revealed that twins have IQs which are lower than that of singletons of the same age in the formative years. While young twins struggle to achieve cognitive proficiency, eventually they catch up with their peers quickly and perform just as well.
Cousins and siblings at the same time
If an identical pair of twins marry another identical pair and both couples proceed to get children, the kids are cousins. Furthermore, they are genetically siblings! If a researcher would examine the DNA of each child, they would not be able to tell who the child belongs to. That’s because both couples have the same DNA. Interesting right?
Twins are biologically astonishing. Many people love to simply observe them. With twins, there is so much more than meets the eye. These facts prove this beyond a shadow of a doubt!