Thousands upon thousands of words have been written about research into parent-child relationships and couples' bonds.
But when it comes to studies involving one of the longest and most significant relationships a human can have — that of adult siblings — research is scant, according to University of Maryland School of Social Work professors Geoffrey Greif and Michael Woolley.
In their new book, "Adult Sibling Relationships," published by Columbia University, Greif, 66, and Woolley, 58, explore the often understudied affection, ambivalence and ambiguity of sibling relationships through the lens of middle-age adults and older. The book, suggested for therapists and siblings looking to better understand or improve these relationships, encourages clear communication, forgiveness and looking to the past to identify sources of conflict to make amends and foster stronger bonds.
"The relationships we have with our siblings are the longest relationships we'll ever have. We have them longer than our parents, our partners, our children and probably longer than our friends in most cases," Greif said. But in the world of social work and therapy, "we don't have a language for siblings who don't get along," said Woolley, who himself has relationships varying in closeness with his five siblings.
Greif, who has studied male friendships, couples and parent-child relationships over a 30-year career, called on Woolley, director of research for the Maryland Longitudinal Data System Center, to co-write the book and help with statistical research.
Their research probes the relationships of 262 people between ages 40 and 90. Each subject has at least one living sibling, a benchmark that allowed the authors to explore the dynamics of more than 700 siblings through in-person interviews, writing prompts and multiple-choice questions.
Upbringing, according to the authors, was a distinct factor in sibling relationships later in life.
"When parents showed favoritism or interfered in sibling conflict, those adult siblings were more likely to tend to conflict, and they were less likely to collaborate in the care of older parents," Woolley said.
Simply put, "if adult children get along better, they'll take care of their parents better," said Greif, who is the youngest of three siblings.
The authors also found that the dynamics of sibling relationships during childhood often transferred into adulthood. A relationship that lacked trust in childhood was likely to have a similar emotional status later in life, Woolley said, while a person who had a positive emphasis on sibling relationships during childhood often found those relationships to be strong in adulthood.
Liz Hergenroeder Pepple, a psychotherapist and participant in the study, is one of 12 siblings and identified with this finding.
From the days of working in her family's deli and bakery in Gardenville, the 68-year-old Towson resident remembers being required to collaborate and work with her four brothers and seven sisters daily. It meant doing almost everything with them.
"We were each other's best friends," said Pepple, recalling the Sundays when she and her siblings would split a bag of Hershey chocolates or divide the seeds of a pomegranate among the 12 after a day's work. Since then, they have all experienced the ups and downs of growing older together, Pepple said, including the devastating deaths of their parents and four of their siblings, three of whom died of cancer.
"It's still incredibly painful. You'd think you have died yourself," Pepple said. "The pain is so excruciating."
The closeness she felt growing up with her brothers and sisters remains, but she has experienced some of the ambiguity Greif and Woolley write about — especially once the lifelong Democrat realized one of her siblings supported presidential candidate Donald Trump.
"I hadn't realized that I had sisters [who] are Republicans. I went, 'What? When did that happen to you?'" she said.
The book embraces the congenial aspects of sibling relationships — and the less loving.
"We all know we should have affection for our siblings, but what if we don't? What if we're a mixed bag?" Woolley said.
According to Greif, most people are "mixed bags" of emotions. Seventy percent of subjects said their relationship with another sibling had waxed and waned.
One minute, we praise our siblings for their undying support, Greif said; the next, we complain. The book's research shows that relationships are often "gray" or ambiguous, fueled by very different experiences and personalities.
"That's one of the things we're trying to do with the book — just telling people that it's OK that they have a wide range of strong feelings about their siblings," Woolley said.
Family therapist Karen Gail Lewis, who practices in Silver Spring, has been helping siblings in their relationships via therapy and weekend retreats for more than 30 years. Used as a source in Greif and Woolley's book, Lewis said that sibling relationships over time resemble an hourglass figure.
"In childhood, siblings tend to be close — that's the bottom of the hourglass. And as the waist ... is getting smaller, this represents the 20s and 30s, when we're less close and we're living our own lives," Lewis said. "Then [the hourglass] moves out again as the kids are growing up and spending more time with their larger families, and siblings now have closer contact with each other. The top of the hourglass is old age, when siblings become more important."
Lewis found that siblings tend to keep in touch the most after the age of 65, which is all the more reason to seek help for sibling conflicts or rivalries now, she said.
Greif and Woolley's book offers suggestions for both mental health practitioners and those interested in improving and exploring the many complexities of their sibling relationships. Drawing upon three theorists, including Argentinian family therapist Salvador Minuchin, Greif and Woolley stressed the importance of setting boundaries, ensuring that parents don't interfere too often or project favoritism, which can cause conflicts between siblings well into adulthood. Subjects Greif and Woolley interviewed also emphasized clear communication and making an effort in the relationship as ways to improve bonds.
"They must be willing to make the initial effort and then a continued commitment to reignite the relationship and keep it alive," Greif and Woolley stated in the book.
Greif and Woolley said their work is not done.
"We had too much fun with this book not to do another," Woolley said.
The two have begun their first wave of research for their next book on a topic that will likely resonate with many married couples — relationships with in-laws.
If you go
Greif and Woolley will appear at 11 a.m. Feb. 6 at the Enoch Pratt Library in Roland Park.
Improving adult sibling relationships
Here are four tips from "Adult Sibling Relationships" on ways to foster and rebuild your sibling relationship:
Communicate: "Communication clearly and through 'I' messages can help undo past patterns of people not sharing their feelings or relying on blaming, distracting, and placating," Greif and Woolley stated in the book. Sharing feelings can put us in a vulnerable place and listening takes effort, but with high risks come high rewards, Greif and Woolley wrote.
Forgive: It's essential to let some of the past hurts and rifts go. Considering a balance is also vital. Is forgiving your brother or sister and moving on worth establishing a relationship? If so, imagine and focus on what that future relationship might look like and work toward it, the authors suggested.
Make the effort: Just "being there" and putting time and work into the relationship ranked high in importance for many of the sibling subjects Greif and Woolley interviewed. As people get older and more responsibilities fall on their plates, it's common for siblings, and people in general, to drift apart. But taking the first step and making the effort to rebuild can "reignite the relationship and keep it alive," the authors wrote.
Embrace the ambivalence and the ambiguity: We can't know everything about our siblings, and what we do know about our brothers and sisters, we don't have to like. "The journey we take with them may not always be easy but if we know they are riding along with us, we feel safer, the bumps along the way may be smaller, and the ride a lot more fun," the authors wrote.