Exhaustive Study Notes on Separated Chinese Twins and Twin Research

Background and History of Chinese Adoption Twin Separations

In the late $1970\text{s}$ , China instituted its official one-child per family policy, which led to the abandonment of more than $100,000$ infants, the vast majority of whom were girls.
Overflowing Chinese orphanages prompted the authorization of international adoptions beginning in the early $1990\text{s}$ .
When international demand for healthy Chinese infants outweighed the available supply, orphanages began separating biological siblings and twins during the adoption process.
The Chinese government never established an official policy regarding the adoption or preservation of twin placements.
Naturally occurring twin births take place in approximately $1 \text{ in } 80$ births ( $1.25\%$ ).
Estimates indicate that as many as $1,500$ sets of twins—comprising both fraternal and identical pairs—were separated through international adoptions.
Dr. Nancy Segal is a professor at California State University, Fullerton (Cal State Fullerton) and serves as the director of the Twin Studies Center.
The forced separation of Chinese twins provides scientists with a unique research pool to evaluate human development and determine the comparative influences of nature (genetics) versus nurture (environment).

Case Study: Evie Hanlon Moores and Eva Chia

Evie Hanlon Moores and Eva Chia are identical twin sisters who were separated in China as infants and raised $10,000\,\text{miles}$ apart.
Evie Hanlon Moores was adopted by Jo Hanlon Moores and grew up near Bath, England.
Eva Chia was adopted by Dee Cridland and grew up in Brisbane, Australia.
Dee Cridland brought baby Eva home to Australia when she noticed photographs of another infant posted on an online adoptive parent website by Jo Hanlon Moores.
Dee Cridland recognized that the child in the posted photos looked identical to Eva; Jo Hanlon Moores had adopted Evie $3\,\text{months}$ prior to Dee's adoption of Eva.
Subsequent DNA testing confirmed with certainty that Evie and Eva are genetically identical twins.
Giving the girls similar names—Evie and Eva—was an odd, independent coincidence by their respective adoptive parents.
Upon learning of the separation, Dee Cridland—who already had $3$ biological sons—was so distraught by the separation that she initially considered giving Eva up to Jo Hanlon Moores so the sisters could be raised together in England.
Dee Cridland and Jo Hanlon Moores established a mutual commitment to ensure the twins maintained regular contact throughout their lives.
Evie Hanlon Moores and Eva Chia met in person for the first time at the age of $3.5\,\text{years}$ old; by age $11$ , they had met physically in person only $4$ times.
Despite living $10,000\,\text{miles}$ apart, both girls exhibit identical running styles, laughs, non-verbal mannerisms, and speech patterns.

Case Study: Sarah Heath and Selena Kupinski

Sarah Heath was adopted from China in $1992$ and was raised in Nashville, Tennessee.
Selena Kupinski was adopted from China and grew up in New York City, later attending college in Ohio.
During her freshman year at Georgetown University, a male classmate mistook Sarah Heath for Selena Kupinski, whom he had known from high school in New York City.
The male classmate sent a photograph of Sarah Heath to Selena Kupinski; Selena initially mistook the photograph of Sarah for a photograph of herself, noting that the only discrepancy was that she did not own the clothing shown in the picture.
Social media misconnections delayed their interaction, but after nearly $4\,\text{years}$ of intermittent communication, Sarah Heath and Selena Kupinski arranged to meet in person for dinner.
DNA analysis revealed a $99.9\%$ probability of identical twinship between Sarah Heath and Selena Kupinski.
Sarah Heath and Selena Kupinski became the $18\text{th}$ pair of twins adopted from China to enroll in Dr. Nancy Segal's twin research study at Cal State Fullerton.
After $2\,\text{years}$ of contact, the sisters noted striking similarities, including identical mannerisms while eating pasta, identical drinking and laughing habits, shared aesthetic preferences, and matching photo poses.

Case Study: Jillian Shaw and Lily McCloud

Jillian Shaw and Lily McCloud (also referred to as Billy McCloud) are identical twins adopted from China in the year 2000$.\n* Jillian Shaw grew up in Windsor, Canada, as part of a family with an older brother and sister, raised by her adoptive parents, Mike Shaw and Lynette Shaw.\n* Lily McCloud grew up as an only child outside Toronto, Canada, raised by her adoptive parents, Kirk McCloud and Allison McCloud.\n* Mike and Lynette Shaw met Kirk and Allison McCloud in China in 2000 while undergoing the adoption process for their respective daughters.\n* After observing the striking physical similarity between the two infants in China, both sets of parents ordered DNA tests upon returning to Canada, which confirmed that the girls were identical twins.\n* The Chinese orphanage intentionally assigned both infant girls to the exact same adoption travel group heading to Ontario, hoping the prospective parents would discover their twin relationship.\n* Physical expressive traits between the two girls exhibit mirror-image symmetry: Jillian Shaw is left-handed when writing and parts her hair to one side, whereas Lily McCloud is right-handed and parts her hair to the opposite side.\n* For 16\,\text{years} $, both families sustained regular visits by making alternating$ 4\,\text{hour}$$ drives between Windsor and Toronto.
Lily McCloud identified her twin sister Jillian Shaw as representing the single most important relationship in her life.

Twin Research Findings and Biological Insights from Dr. Nancy Segal

Empirical findings from studies on twins raised apart show that twins raised in separate environments exhibit as much personality similarity as twins raised together in the same household.
Scientific evidence demonstrates that behavioral and personality similarities observed among co-habitating family members are predominantly attributable to shared genetics rather than shared home environments.
Over time, twins raised in separate environments frequently become more similar to one another rather than more distinct.
The increase in similarity over time occurs because independent adult twins gain the autonomy to gravitate toward environments, hobbies, and experiences aligned with their underlying genetic predispositions, free from parental direction.
Environmental nurture provided by adoptive families serves to enable underlying biological nature to manifest fully.
High degrees of genetic heritability are observed across non-verbal mannerisms, distinct laughter patterns, physical gait, precise word choices, and vocal cadence.