Twins: Exploring Nature versus Nurture

Amy-Ruth Gyang, Editor

A blessing and a curse, twins have been praised for their duality and mistreated for their rareness. Twins have left their mark on literature to modern day genetics to the entertainment industry. Their past stereotypes and misconceptions have allowed for scientists to better understand their individualities and genetics.

Twins fascination, despite its ups and downs, is still present today. The rise in twins, over the years, has increased with greater developments in fertility treatments. According to the Centers for Disease Control and Prevention, a 2018 study found that 3.26% of births in the U.S. were twins and about 1⁄3 were identical. In the past 30 years, the birth rate of twins has increased by 76 percent. The higher rates of twins, in the population, has increased scientists and psychologists’ knowledge on the factors that can influence twins’ characteristics.

Research conducted by Michigan State University shows that twins have long been important as they’ve allowed scientists to ponder how much of a human’s personality arises from genes versus environment. Genes or genetic traits are passed down from parents and can influence twins’ physical features and behaviors while the environment affects a twins’ culture and social influences.

“Nature versus Nurture is a classic argument in Psychology that seeks to discover how much of who we are is due to our genetic programming, and how much of it is due to environment,” said Social Science teacher Donna Walker, who teaches AP Psychology. “I teach my students it’s baby you versus everything that has happened to you since conception. Some twins, despite being born into different environments, can still share the same personalities.” 

Because identical twins share the same genetic makeup they allow scientists to easily compare the roles their genes and environments have on their personality and social interactions. Genetic sequencing in twins has allowed scientists to discover which genes, in twins, may differ and how that makes one twin prone to a disease and not the other twin or even comparing the change in genetic makeup of twins going to space.

Twins increase in the population has led to a change in legislation regarding twins in school. 14 states, including Florida, have laws mandating the separation of twins in school, although it hasn’t been proven scientifically to benefit a twin. MBF, The Multiple Births Foundation, states that around ⅓ of twins are separated in school.

“My observation, and what clinical advice offers, is that it depends on the twins. There could be positive or advantageous reasons towards both keeping them united and separated, it really depends on the situation, there isn’t a blanket rule,” said Walker.

At Trinity, it’s not often that twins are in the same classes. For fraternal twins, juniors Layla and Levi Kaplan, this is their reality.

“I think it’s cool going to school together, I personally like it,” Levi said, “I think separate classes were good for individual development, but I appreciate now having some classes together, and being able to have banter with each other makes [class] more enjoyable.”

Twins separation can alter a twin’s personality, due to the environment, but factors such as genetics can still affect their appearance and physical conditions. Twins could be separated and still take interest in similar hobbies, sports and interests.  

“Growing up, we always did everything together, and now it really isn’t much different,” Levi said. “We both have the same interests in a lot of stuff, like theatre, tennis, and playing music, but there are some differences. She likes to draw and I don’t. I enjoy reading plays and her not so much.”

Similarities in genetics and environment can allow for twins to have a close bond. For centuries many have claimed that twins share a unique physical and mental feeling, twin telepathy.

Although they’re twins, Layla and Levi Kaplan ‘22, both have very different artistic hobbies. While Levi enjoys acting, Layla enjoys drawing.
(KAYLA ALEXANDRE and Henry Van Voorhis )

Nancy Segal, PhD, director of the Twin Studies Center, at California State University, Fullerton, says that scientific research doesn’t support the idea. Twin telepathy is more reliant on their shared environments or genes.

“Emotional pain we do sometimes share and we share a lot of thoughts, but we don’t share physical pain,” Layla said.

Shared experiences, similar genetics, and personalities are all determinants of how a twin might react. Telepathy isn’t only limited to twins, as siblings and friends with similar character traits, interests and experiences can also form these telepathic bonds.

“We can’t feel each other’s pain, which I’m pretty thankful for since she’s a total klutz, but as far as telepathy, we can somewhat read each other’s minds,” Levi said. I don’t think it’s restricted just to twins, but we both have similar ways of reading situations, and a simple raise of the eyebrow can tell the other twin everything they need to know.”