“If I get to 60 or 65 years old and my kids don’t talk to each other, I will view my whole life as a failure,” a father of four young children told me the other day.

“Really? Your whole life a failure?” I asked.

“Yeah, a failure,” he said.

Without much effort, I could think of a few families with adult siblings who don’t speak to each other. Even more easily, I could think of many families in which adult siblings treat each other with lightly veiled disdain or, at the very least, a lack of interest.

“We talk to each when we have to,” a woman told me about her sister. “We’ll go to parties for my parents, or Thanksgiving. But other than that, we rarely see or talk to each other. We have so little in common and have long ago stopped pretending that we do.”

Is there a link between your parenting style and the quality of your children’s relationships with each other? If your children get along famously, is it because you did something right? Did adult siblings who despise each other loathe each other when they were children?

According to the most recent Census, between 2000 and 2004 the number of children under 5 in Manhattan increased by 26%. As more and more young children are being raised in New York City, it goes without saying that there will be more and more sibling rivalry. After all, there is only one sibling relationship in a family with two children, compared to three potential minefields in a family of five.

Research suggests that sisters are closer than brothers, who are closer than opposite sex siblings. It also shows that rivalry is greatest among siblings two to four years apart, particularly when they are same-sex.

Several studies I read on the subject link parenting style and sibling discord. According to a University of Georgia researcher, Gene Brody, lower sibling conflict levels are associated with a father’s equal treatment of his children, a mother’s balanced approach to controlling her children, family harmony during family discussions about sibling problems, and parents’ perceptions of family cohesiveness.

What I found alarming in Mr. Brody’s research was the conclusion that “data suggest not only that the quality of the sibling relationship is stable from middle childhood into adolescence, but that rivalrous feelings originating between siblings in childhood persist well into adulthood and are associated with the closeness of adult sibling relationships.”

So when I worry about the ups and downs of my children’s relationships with each other, the concern is not misguided.

“Next year at school is going to be the best year,” my son told me enthusiastically last week.

“Why?” I asked.

“Because I will be in third grade and Josh will be in first grade and the sports day is for the first-, second-, and third graders. It’s the only year we’re going to be together,” he explained.

This is my most recent solace, as these feelings of warmth come from a child who has spent a significant part of the last four years trying to hit, scratch, and kick his younger brother into oblivion. I was ecstatic to hear this sign of affection for his younger brother.

Not everyone agrees that parenting style plays a determining role in the short- and long-term relationships of siblings. A child psychiatrist I spoke to said that even after reading this kind of research, she feels that ultimately children’s individual relationships trump any other factor.

“The children’s individual personalities play the greatest factor in determining their relationship. Of course their age difference and their birth order matter, too, as does their parents’ approach to them. But there are so many conflicting studies. In the end, and certainly for the duration of their lifetimes, their personalities determine the strength of their relationships,” she said.

She added that parents of adult children often have unrealistic expectations for their children. “As a parent, you worked hard to create a warm, loving family. But as your children go to college and get married and create their own families, their priority is naturally going to be on their own families, not the ones they came from,” she said.

The woman who rarely speaks to her sister echoes this sentiment. “For years it drove my parents crazy that we didn’t have a close relationship. They nagged us all the time. Of course they want us to be those idealized sisters. And the truth is, I wish I had a sister that was my best friend. What could be better? But we both have good marriages and healthy children, and that needs to be a good enough sign of success for my parents,” she said.

Good enough. When it comes to being parents, that is often the secret to success.

sarasberman@aol.com