What Does the Research Tell Us About Twins Sharing the Same Classroom?


As a writer of twin issues for more than a decade, there’s one question I hear time and again from parents of multiples: “What does the research tell us about the effect classroom separation has on twins?” Although there are only a handful of long-term studies that address this important twin topic, the good news is that nearly all of them conclude that twins who share a classroom do just fine when it comes to identity formation and even academic achievement. Although that’s a huge relief for many parents of twins grappling with the issue, they should proceed with caution as the research often doesn’t tell the whole story. There are always extenuating circumstances that parents of twins should consider before asking to have their duo share a classroom.

Twin Research and Reading Skills

Two blonde twins dressed in red shirts.

Back in 2009, for instance, researchers looked at the effect of classroom separation on 1,500 kindergarten through second-grade, same-sex twins from the United States and Australia. They wanted to see if classroom assignment had a cumulative effect on the twins’ reading abilities by the time they reached third grade. At first, their results showed that those twins who shared a kindergarten and first-grade classroom actually had higher reading scores than those twins who were separated. But when the researchers adjusted for pre-existing differences between the twin pairs such as disruptive behavior and preliteracy capabilities (two factors that parents consider before making the placement decision), classroom assignment no longer had any effect. In addition, the researchers found that by grade two, classroom assignment made no difference at all in the twins’ reading scores. Although this study (and several similar studies conducted previously) indicates that classroom placement has no effect on a twin’s ability to learn to read, many parents of twins caution that having their twins share a classroom was actually a hindrance to their success.

“Both my boys were behind in reading when they entered the same second grade classroom,” says Ellen Warila of her nine-year-old fraternal twin sons, Luke and Jacob. But with a little extra help, explains this Lancaster, Mass. mother of four, Jacob became a voracious reader and quickly finished well above grade level by the end of the year. Luke, on the other hand, continued to struggle requiring an individual reading specialist for the rest of the school year. Warila believes that having her boys in the same classroom might have exacerbated the situation by highlighting the boys’ differences in learning style. “Luke is very competitive and I think it really bothered him that Jacob is such a better reader.” It was then that she decided to separate her sons the following year. Although it’s still a struggle to get Luke, now in fourth grade, to read for enjoyment, she says he is making great strides in his reading ability.

Mary Inman of Egg Harbor, New Jersey had a similar experience with her now 16-year-old fraternal twin daughters, Abigail and Amanda. “Our daughter Abigail excelled in school while Amanda struggled. They were together until the fourth grade when we had to separate them for this reason,” says Inman. “Once they were separated they both seemed to blossom. Abigail got a teacher who really challenged her to achieve her total potential and Amanda got a nurturer who really helped her succeed. She actually improved by two grade levels that first year.”

The take-away lesson for parents is an important one: Before deciding on classroom placement for your twins, consider each child’s learning style. Although twins on equal academic footing will probably do just fine in the same class, separate classrooms allow each twin to develop skills at his own pace, free from the pressure and comparison of a cotwin.

Twin Research and Classroom Behavior

How twins fare academically is just one side of the classroom separation debate; how they behave together or separated is the flip side. And once again, we turn to the research to help us.

In 2005, a study done in the Netherlands looked at both the short- and long-term effects of classroom separation on behavior as well as academic performance on a group of more than 7,000 twin pairs. Researchers studied the group at various developmental stages—at age three, five, seven, and then finally at age twelve. At first, they found that both in the short and long term, those twins who were separated experienced more internalizing problems (anxiety, low self-esteem, shyness) and externalizing problem behavior (acting out, tantrums, defiance) than those twins who were together. But when researchers went back to the data attained at age three and adjusted for pre-existing behavioral problems, separation did not affect externalizing problem behavior or academic achievement in both the short and long-term. But, they did find that those twins who were separated at age five had more internalizing problems at age seven but these negative feelings disappeared by age twelve.

Translation? Separation doesn’t have a long-term negative effect on twins but it may in the short term for some twins. So what does that mean for parents? If your kindergarten-bound twins are tightly bonded, have a difficult time making friends, and have never spent much time apart, you may want to consider placing them together for the first year or so. In the end, however, it’s up to the parents to try to tune in to the subtleties of their twins’ relationship before making any placement decisions.

That’s a lesson Nely Artis learned first hand. When this Katy, Tex. mother of three enrolled her fraternal twin boys, Jacob and Joshua, in kindergarten, she requested that they be together as separation in the past had backfired. And thanks to the twin bill that recently passed in her state, her school complied. But Artis quickly realized that some of her sons’ classroom antics just weren’t going to cut it and their behavior became a problem. It seemed her boys loved to tattle on each other. “They were constantly trying to figure out what each other did so that they could come home and tell us,” she explains. “We had several parent-teacher conferences and the teacher told us that they also paid attention to each other’s work and not to their own work.” Although her sons did well academically in kindergarten, Artis chose to separate them the following year simply because of their questionable behavior. “Now they can concentrate on their own achievements instead of focusing on each other’s weaknesses and failures.”

The Bottom Line

It’s great that parents of twins finally have some research in which to not only help them decide how to place their twins in school but also to present to misinformed school administrators who continue to arbitrarily separate twins. If you’re sparring with your school district about trying to keep your twins together in the same classroom, the research is clearly on your side. But remember, every set of twins is different and yours may benefit more from having less face time with his cotwin. And one great way to offer each a bit of independence and breathing room is to separate them in school.

A copy of the book Double Duty.