Adult Sibling Rivalry

Sibling rivalry often lingers through adulthood.

By Jane Mersky Leder, published on January 01, 1993 - last reviewed on July 14, 2009

Although both twins said living in different states as adults was not a conscious decision, they've only been geographically close for one six-month period, when they both found themselves living at home. "Marv tried to control my life by telling me what to do and when to do it," Mel said. "I was brought to tears many times. He said things I'll never forgive him for. I was shocked. It was like we were kids again." "It was not pretty," said Marv. "Space has a lot to do with our relationship, and we irritated each other a lot. Seeing Mel's lack of consideration and selfishness, I regressed and didn't handle things as well at first. I did a lot of yelling, just like I used to." The twins didn't see each other again for about six months. And when they did get together, it was, Mel said, "pleasant but distant."

When I recently called to talk to Mel and Marv to see what improvements, if any, they'd made in the last three years, Mel was enthusiastic about a follow-up interview. But Marv didn't think it was a good idea, and was hurt that Mel had agreed without consulting him first. "We need to work through some stuff brought up by the last interview," he said. "We need to do a lot of soul-searching. We keep saying we're going to do it but never seem to make the time." While Mel was disappointed, he deferred to his brother's concerns and ultimately decided not to discuss their relationship with me, either.

What makes brother/brother ties so rivalrous? Gold has launched a new study that is not yet completed. But she has found a consistent theme running through the interviews she's conducted thus far. "The thing that rides through with brothers that doesn't come across in other sibling pairs is this notion of parental and societal comparison. Somehow with boys, it seems far more natural to compare them, especially more than with sister/brother pairs. Almost from day one, the fundamental developmental markers--who gets a tooth first, who crawls, walks, speaks first--are held up on a larger-than-life scale. And this comparison appears to continue from school to college to the workplace. Who has the biggest house, who makes the most money, drives the best car are constant topics of discussion. In our society, men are supposed to be achievement-oriented, aggressive. They're supposed to succeed."

Sibling relationships are not fixed, however; they change dramatically over the years. Key life events in early and middle childhood can bring siblings closer together--or split them further apart. Dunn found that such events as a mother's illness and, in one case, a mother's death prompted siblings to be tremendously supportive of one another and to close ranks in the face of stress. The transition to school, on the other hand, diminishes the relationship between older and younger siblings.

Similarly, life events in adulthood--leaving home, getting married, tending to an ill parent, grieving over a parent's death, adjusting to an empty nest--have the power to significantly alter the connection between siblings or to reinforce old rivalries. When it comes to the marriages of our siblings, for example, we are not unlike ex-husbands or ex-wives.

"Our brothers and sisters were our 'first' marriage partners," says Karen Lewis, a counseling psychologist and coeditor of Siblings in Therapy, a collection of writings about siblings. "We have a lot of emotional stock invested in them and in the spouses they choose." How will their entrance into the family affect how we all get along? Are our sisters- or brothers-in-law like us? Are they good enough to be one of the family? Apparently, many are not. In one of the few studies of young- and middle- adult siblings, two-thirds of the siblings interviewed said that the marriage of their brothers and sisters drove a wedge between them. Their already-conflicted relationships were exacerbated, or sibling relationships that appeared sound suddenly became strained.

In the interview I conducted for my book on siblings, stories of strained relationships following one or the other's marriage far outweighed stories of marriages that enhanced the sibling connection. In several cases, the spouse was "not like anybody else in the family." Siblings found it difficult to try to get along with sisters- or brothers-in-law who were different and sometimes difficult. For some, the new family member was seen as someone who made an effort to keep siblings apart.

"She would not let me come near my brother;" a disgruntled sister recalled. "He was cold and controlling. My brother and I weren't part of each other's lives. I felt empty then, like I was floating in space." Another sister talked about the "great change in the quality of our relationship" after her brother married. "The focus went from me being the critical person in his life to his wife being the most important. I was sad... sad that a discrete life stage had come to an end."

Yet another sibling talked about how his sister's husband destroyed their relationship. "He had some business dealings with my company that were rather shady. I never forgave him for that or my sister for marrying the guy." For some rivalrous siblings, divorce offers another chance to improve the relationship. In a few cases, adjustments are made. For the others, the rift can last a lifetime.

Perhaps the most devastating consequence of sibling relations gone bad is sibling incest. While it's difficult to estimate how many siblings are sexually abused by a sibling, a study by sociologist Diana Russell of San Francisco found that 16 percent of 930 women over 18 had been sexually abused by a sibling. Extrapolation to the population at large reveals that 160,000 women under age 18 have been incestuously abused, and 23,000 per million have been victimized by a sibling.