Psychology Facts

▲ Twins ▲

》Identical twins, sharing the same genomes, are always of the same sex. Conversely, fraternal (dizygotic) twins stem from the fertilization of two distinct eggs by two separate sperm during the same pregnancy. They share half of their genomes, akin to any other siblings.

》Twins exhibit a higher prevalence of left-handedness compared to singletons. Approximately one in five pairs of twins (22%) have at least one left-handed individual, which is double the rate observed in singletons (10%).

》Twins are more frequently female than male. However, male embryos have a higher mortality rate in utero compared to female embryos. Additionally, the overall mortality rate for twins in utero is higher than for singletons.

》Approximately 25% of identical twins exhibit a phenomenon known as "Mirror Image Twins," where they are exact reflections of each other. For instance, if one twin has a freckle under their left eye, the other twin's freckle will be under their right eye.

》Fraternal twins, resulting from the fertilization of two separate eggs, can vary widely in appearance and genetic makeup, much like any other siblings. They may resemble each other closely or have entirely different physical characteristics, including different skin colors.

》Despite sharing identical genetic makeup, identical twins do not have identical fingerprints.

》Connecticut has the highest rate of twin births, with nearly 41.3% of all births resulting in twins.

》Another study published in the Journal of Reproductive Medicine found that women who consume more dairy products may increase their likelihood of conceiving twins.

》Twins, whether identical or fraternal, have fascinating characteristics and differences.
Identical twins, despite sharing the same genetic makeup, can display variations over time due to environmental factors and epigenetic effects.
Fraternal twins, conceived from separate eggs, can have diverse appearances and traits, akin to any other siblings. Additionally, factors like maternal diet may influence the likelihood of conceiving twins. Overall, the complexities and nuances of twin dynamics continue to intrigue researchers and enthusiasts alike.

》Conjoined twins, due to their physical connection, may share sensory experiences such as touch and taste through a thalamic bridge, enabling them to perceive sensations felt by the other twin.

》The New York Times once published an article suggesting that conjoined twins possess a "neural bridge," implying that they can read each other's minds.

》Researchers speculate that twin babies might use each other as language models, particularly in cases where exposure to adult language is limited. These autonomous languages, consisting of inverted words and onomatopoeic expressions, are developed by twins who closely interact and communicate with each other as they learn to speak alongside each other.

》Researchers from the University of Padova in Italy conducted a study involving 3D ultrasound videos of five sets of twins in the womb. They observed that at just 14 weeks old, the fetuses exhibited behaviors such as reaching out for each other, touching head to head and arm to head. By 18 weeks, they were observed to be stroking each other more frequently, with physical contact occurring approximately 30 percent of the time.

》Approximately 40 percent of twins develop their own language, according to researchers. This phenomenon, where twins mimic each other's babbles instead of their parents' speech, is termed idioglossia or cryptophasia.

》Separated twins who are unaware of each other's existence often lead surprisingly parallel adult lives.
For example, the "Jim Twins," as reported by Live Science, were two separated twins who coincidentally both ended up being named Jim. Upon meeting as adults, they discovered that they had each been married twice — their first wives were named Linda, and their second wives were named Betty. Additionally, both grew up in Ohio, were chain smokers, and drove similar cars.

》Dogs have the ability to distinguish between identical twins. In a 2011 study published in the journal PLOS One, German shepherd police dogs were presented with the scents of identical twins. Despite living in the same household and consuming the same food, the dogs were able to identify the exact matches among jars containing scents from other individuals, demonstrating their remarkable olfactory abilities.

》Taller women have a higher likelihood of having twins, possibly due to elevated levels of insulin-like growth factor (IGF). IGF, a protein released by the liver that stimulates growth in long bones, is found in higher concentrations in taller women. This hormone also increases ovarian sensitivity, leading to a greater likelihood of ovulation.

》Researchers from the University of Utah found that mothers of twins tend to live longer than other parents. They arrived at this conclusion after analyzing the birth records of over 59,000 women spanning from 1800 to 1970.

》One way to differentiate identical twins is by examining their belly buttons. These are essentially scars formed at the site where the umbilical cord attached the baby to the mother, and they are not influenced by genetics.