F rior, when she was little, she often went to the garage next to the house to sing. Two, sometimes three hours long. Singing just made her happy, she couldn’t get enough of it. She had barricaded herself in the garage because her singing in the house got on everyone’s nerves terribly.
"Shut up already!", her sister often screamed, says Katharina. Margrit, who now lives several hours away from her by plane, will probably tell us how much this drove her crazy at the time.
When she thinks back to growing up with her sister, says Margrit on the other side of the world, she can’t think of too many things that she found beautiful. But this: on the way to school, which they always walked together, Katharina loved to sing. "She could sing like a bird, and to hear that, that calmed my often troubled soul, somehow," Margrit says.
She has a serious look, but the same straight blond hair as her sister, the same cheeks that blush quickly when it’s cold or she gets excited. Both speak quickly and melodiously. If you only hear their voices, you can hardly tell them apart.
Katharina and Margrit are fraternal twins. They were born on a July day 38 years ago and have spent their entire childhood and adolescence together. They had some good times together and a lot of bad.
"You think twins understand each other without words and love each other without ifs and buts," says Katharina. "But that was not the case with us at all."The relationship with her sister was always difficult. And always will.
Lifelong effects on personality
Sibling relationships are among the longest, most enduring and intimate bonds in life – but it’s only in recent years that their importance to all other relationships in life has been recognized, and they’ve come into the spotlight of psychology.
Sibling relationships outlast relationships with parents, with many friends, and often with partners as well. You don’t know as much about anyone else as you do about the sister or brother you grew up with. Because they played together, comforted and helped each other. But it’s also because people played off each other, told each other off and hurt each other, left each other alone or shut each other out.
When things go well, the positive experiences outweigh the negative ones. But what if that is not the case? Because problems then begin in early childhood and have lifelong consequences, researchers are interested in complicated sibling relationships. Because they also shape the further development of the children independently of each other: whether they stand out at school, become emotionally unstable, experiment with drugs or come into conflict with the law.
Twins held hands at birth
In the past, scientists have focused a lot on the influence of parents when it comes to child development, says Dutch psychologist Kirsten Buist of Utrecht University. For years, she has been studying the conditions that promote healthy development in children and adolescents.
"We now know that the influence of the sibling on emotional and social development is sometimes even greater than that of the parents."Especially for the social competence and possible problem behavior of children, it is crucial whether the relationship between siblings is on a good foundation.
If she does this, it has a positive, but rather small effect on the development of the children. Siblings who understand and support each other cope better with stressful life events later in life and report a higher sense of well-being in adulthood.
Bad sibling relationships can do a lot of damage
However, if there is no good foundation, the psychologist says, this has a negative effect on the children. And not just a small one, but a frighteningly large one, as a meta-analysis of 34 international studies involving more than 12.000 children, which Buist published last year.
Siblings in high-conflict relationships often show deficits in their emotional development, findings show. They react more anxiously, depressively or aggressively to life’s demands, are less socially competent and more often hyperactive or socially withdrawn and isolated.
The fact that negative experiences are more formative than positive ones is due to the fact that, in the course of evolution, it has been more important for people to learn from negative experiences than from positive ones. For child development, this means that a good sibling relationship helps a bit. A bad one, however, does a lot of harm.
Katharina and Margrit’s relationship was not on a good foundation. "My mother started treating us very differently right after we were born," says Katharina. Why, she does not know until today. "I was breastfed, Margrit only got the bottle. When I complained about something, I was listened to. For example, when Margrit complained about pain in her feet – she really needed shoe inserts – all she was told was: "Don’t be such a baby."Yes, confirms Margrit, for some reason she was the black sheep from the beginning – and Katharina the favorite child. "Was it because she was taller than me?? Pretty? Thin? I have no idea."
At school, the girls were placed in different classes. In fact, says Katharina, it was only after she started school that she understood that her sister could also think and act quite differently from her.
Gradually they developed different interests and views, the first conflicts arose. Although the sisters were treated so unequally, they were also forced to be equal: they shared not only a room, but also their clothes and a bed. Arguing over who got to wear what and who slept where became a daily battle.
The smaller the age difference between children, the more likely it is that they want the same things: the same rights, the same attention.
A research laboratory for life
Sibling conflict is important: It teaches them to compare, measure, disagree and forgive each other. They could make mistakes, misbehave, be mean. Sooner or later you will hurt the other person, maybe you will be left with scars.
But for siblings with a good foundation, none of this will destroy the relationship. A research laboratory for the whole of life, that’s what Joachim Armbrust calls sibling relationships. The psychotherapist from Schwabisch Hall writes books about sibling relationships and their opportunities and risks.
Because you can’t just end a relationship with a brother or sister like that, it offers a very safe testing environment. Siblings are as close to you as your parents, but they do not have their power.
"This relationship becomes a lifelong foundation for understanding trust and consistency with peers," Armbrust says. If the sister treats a borrowed doll well, it makes it easier to trust friends later on.
Twins continue to cuddle even after birth
This video of the newborn twins enraptures many Internet users. It shows the siblings bathing together. They cuddle up to each other as if they were still in the womb.
If you learn to lose to your brother in a dice game, you’ll be better able to take criticism from colleagues later on. Kirsten Buist points out that studies have shown how the behavior learned in a relationship with a sibling is transferred to other relationships on the same hierarchical level – usually without the people concerned being aware of it.
Trust and consistency, both of which Katharina and Margrit had only to a limited extent. Their conflicts over trifles became more aggressive and rarely ended in reconciliation. At twelve, they vowed to be nicer to each other. But over time, Katharina says, Margrit’s anger about unequal treatment became a permanent problem.
She often had the feeling that Margrit was venting her pent-up frustration on her – even if it was only when she was playing ball, where Margrit threw the ball at her sister with all her might. "She never really hurt me. But she recognized my fear of her and sometimes, in a childish way, took advantage of that," she says.
Hate as a sign of deep emotional attachment
Not only at home, but also at school, Margrit got into trouble and sometimes got physical with other children. Today, Katharina can better understand what it must have been like inside Margrit at the time. At that time she thought her sister was just mean.
Katharina also reacted to Margrit’s anger with rage, sometimes even feelings of hatred. Then came the bad conscience again. It was her sister after all.
But hatred, says Joachim Armbrust, is also a sign of a deep emotional bond. In such constellations, they sometimes forget this because of their anger and annoyance with the other person.
"Children simply have a very fine sense of injustice," says the psychologist. It’s not always intentional on the part of the parents, who often don’t even notice. But children so easily get caught up in a whirlpool of aggression – with long-term consequences, as researchers have recently shown.
Corinna Jenkins Tucker of the University of New Hampshire reported in July that constant aggression against a sibling, usually perpetrated by the disadvantaged child, increases the aggressive child’s risk for drug use and criminal activity.
Having to constantly defend oneself against aggression, in turn, increases the risk of depression and anxiety disorders in the favored child, because he or she learns to live in permanent alertness. In the long run, both siblings suffer equally from unfair treatment.
Ibrahim Tanrikulu from the Middle East Technical University in Ankara investigated how often the line between normal sibling quarrels and bullying is crossed in constellations like Katharina’s and Margrit’s. He found that nearly a third of all the children he studied between the ages of 10 and 18 were regularly bullied by their siblings.
Girls bully siblings more often than boys
By comparison, the rate of those subjected to bullying by children other than their siblings was barely 10 percent. It was particularly noticeable that girls bullied more often than boys – probably because girls are more relationship-oriented and like to be in control of social relationships, Tanrikulu says.
During adolescence, explains Kirsten Buist, siblings often distance themselves from each other, even those who get along well with each other. Every child needs its own space in order to develop and mature – and at this age, you just take it.
Often, siblings then seek out areas where they no longer have to compete directly with each other. That’s how it was with Katharina and Margrit. "When Catherine took singing lessons, I preferred to learn a musical instrument.
If I threw myself into aggressive sports, Katharina preferred to do community work," says Margrit. "It was only later, when we were no longer living together, that I also started singing, and Katharina discovered her aggressive side."
Margrit experimented with drugs and discovered art
During puberty, both also began to reflect on who they were and what had made them so. Katharina says she also had strong feelings of guilt at the time. "Sometimes I thought: I’m not a better person than Margrit," she says.
"I was always labeled as the responsible one, the one you can trust and who somehow manages everything – and Margrit was the opposite of all that. Whatever she did, she could not get out of this role." At least not in the family.
"I hated being at home sometimes," says Margrit. "I couldn’t wait to finally be an adult." Already at 19 she moved away from home and completely broke off contact with the family for some time. She enjoyed her freedom, experimented with drugs, discovered art.
For many years, Katharina and Margrit then only had very rare contact, once a year, at Christmas at her parents’ house. There was no real exchange. Katharina married, had a child, found work in the field of science. Margrit, on the other hand, discovered she was bisexual, lived with a woman and became a graphic designer.
Contact remains difficult
It was only much later, when they had been living far away from each other for a long time, that Margrit also sought contact again. It’s still difficult. "Neither of us learned well as children how to deal with anger or fear," says Katharina.
"But the older we got, the more sensibly we could talk to each other." She tries to show Margrit now simply that she would like to take part in her life. "I can’t make up for what happened to my sister in the past," she says.
"But I can try to tell her that I believe in her and that I love her. Despite or maybe even because of everything."Margrit does not talk quite so openly about her feelings for her sister. "We live in two different worlds," she says. "And we will only ever reach a certain level of familiarity. But this is okay for me."
Note: The full names of the twin sisters are known to the editors.