SAEDNEWS: Twins have inspired fascination and speculation for generations, but several popular beliefs about them do not match scientific evidence. From telepathy and identical DNA to twin birthdays and the “evil twin,” these six misconceptions have more complicated answers than they first appear.
According to SaedNews: Identical twins begin with a single fertilized egg that later divides into two embryos, while fraternal twins develop when two eggs are released during the same ovulation and fertilized by different sperm. Both produce two babies who develop during the same pregnancy, but many assumptions about twins go well beyond the biology.
Many twins are exceptionally close because they grow up together and may share both an upbringing and, in the case of identical twins, an almost indistinguishable appearance. But twinship does not guarantee a strong relationship.
Some twins clash from childhood, while others are close when young but struggle to establish separate identities as they grow older. Twin siblings can have very different personalities and, like any other family members, their relationships can become complicated.
Research has found that identical twins tend to have more friends in common than fraternal twins and often begin life with similar personality characteristics. Those similarities can diminish with age, however. Even identical twins can develop into distinctly different people.
Stories about twins supposedly sensing each other’s thoughts or physical pain are widespread, but convincing scientific evidence for twin telepathy remains absent.
Some preliminary research has produced intriguing results. In a 2013 experiment involving identical twins exposed to loud noises, one of four pairs showed a response described as “above chance.” Yet psychologist Tania Johnson told National Geographic that there is still no credible scientific evidence establishing twin telepathy.
Similar reactions may instead reflect twins having grown up in the same environment and developing comparable ways of thinking, choosing, and responding. Their nearly identical genetics could also contribute, particularly when identical twins have been raised separately.
Nancy Segal, director of the Twin Studies Center at California State University, has argued that scientists should remain open to evidence that could someday demonstrate twin telepathy. For now, however, such proof appears distant, if it exists at all.
The familiar “evil twin” is primarily a storytelling device rather than a description of real twins. Its roots reach back to ancient mythology, including Zoroastrian cosmology and its twin spirits, Ahura Mazda (Ormuzd) and Angra Mainyu (Ahriman), traditionally associated with opposing forces. Other ancient traditions likewise contain stories involving twin-like spiritual forces linked to good and evil.
Modern fiction turned the idea into a recurring trope. An evil double may look almost exactly like the protagonist while having a distinguishing feature such as a scar or eyepatch, representing corruption, memory, darkness, or something the character wants to escape.
In these stories, the twin often symbolizes an internal or worldly conflict. Real twins, however, do not divide neatly into a “good” child and a “bad” one. Like everyone else, they can contain different and sometimes contradictory traits.
Because identical twins originate from one zygote, they were long assumed to possess identical genetic material. Their DNA is indeed remarkably similar, but it is not necessarily exactly the same.
A 2021 study reported that 15 percent of identical-twin pairs had one twin with significant genetic mutations. Another study examining 381 identical twins found only 38 with no identifiable genetic mutations distinguishing them. Such differences can develop through mutations occurring either before or after the embryo divides.
There is no established evidence that identical twinning is inherited through families. Fraternal twinning, by contrast, can have a genetic component.
The probability of having twins also rises with age, according to UT Southwestern Medical Center. In addition, having previously experienced a twin pregnancy can increase the likelihood of another twin pregnancy fivefold.
Twins do not necessarily arrive on the same calendar day—or even in the same year. If both babies are developing during the same pregnancy, they are considered twins.
Birth can become prolonged or complicated, allowing a substantial gap between deliveries. The longest recorded interval between twin births was 90 days. It occurred in 1996, when one baby was born prematurely and doctors stopped the mother’s contractions, allowing the second baby to remain in the womb.
