July 20, 2010 -- For more than three decades, Dan Trimble thought he had a picture-perfect marriage. He and his wife, Grada, had two daughters and what he considered a life of adventure.
While it may sound like hyperbole, experts say divorce can become "contagious" in close social groups.
"Think of this 'idea' of getting divorced, this 'option' of getting divorced like a virus, because it spreads more or less the same way," University of California, San Diego professor James Fowler told "Good Morning America."
"When one person experiences divorce, it gives the people around them information about what that's like," he said.
According to new research done by Fowler, along with professors Nicholas Christakis and Rose McDermott, being friends with someone who gets divorced makes someone 147 percent more likely to get divorced themselves. A person who has a sibling who gets divorced is 22 percent more likely to also split from his spouse, the researchers say.
CLICK HERE to get Terry Real's tips on what you can do if your relationship is threatened by another couple's divorce.
Fowler said someone does not necessarily have to get divorced himself to change the way divorce is viewed in a social group.
"You might have a friend, for example, who gets divorced, and that changes your mind about whether or not this is an appropriate option. And then you go and talk to a different friend about whether or not they should get divorced. And so one person's divorce can travel through the network even though the person in the middle isn't really affected," Fowler said.
Husband: 32 'Very Good Years' Ended in Divorce
"The 32 years we were married, for the most part, were very good years," Trimble told "Good Morning America." "We had a lot of memories. I was active duty Air Force. We were traveling all over the world."
In the final years of his marriage, Trimble said, he and his wife had begun to grow apart. Trimble says at the time he did not realize that he and his wife were developing separate interests.
Then, two years ago, his daughter, Alycia Sheley, and his grandchildren, moved in with Trimble and his wife.
Sheley said she was having trouble in her marriage and decided to seek a divorce.
"In my family divorce was still a stigma; it was still a bad word. No one got divorced; you just didn't do it, no matter what was going on in your marriage you stuck it out," Sheley said. "To stand up against that ... took a lot of courage for me."
Within a few months, Sheley said, she started dating an old friend from high school. Sheley soon found happiness in the new relationship, she said, and she moved out of her parents' home. In October 2008, she married the man she began dating while living with her parents.
Trimble said seeing his daughter experience divorce and then find happiness changed his wife's perspective on their marriage. Just a month after Sheley remarried, her mother asked Trimble for a divorce of her own.
Trimble and his daughter said they believe her divorce and new life "inspired" Trimble's wife.
"Seeing how I came through it and came out on the other side in a better place and lived to tell about it, essentially kind of pushed [my mother] to stand up and say, 'I am not happy in my own marriage,'" Sheley said.
Trimble said that while he does believe his wife decided to divorce him because of his daughter's example, he does not blame his daughter.
Instead, he said, he compares their relationship to an immune system.
"If your immune system is up to full speed, and you're good and healthy, you're eating right, you're sleeping right, you're getting exercise ... you can be subjected to people who have colds and flu," he said. "But if your immune system is run down, and you get up against somebody who's got a cold or maybe has the onset of the flu, you're a pretty good suspect for coming down with it.
"I kind of think in my own particular situation, my marriage was a lot like that," he said. "The best way I can describe it is as a disease."
Trimble said his daughter's decision to leave her husband -- and then to begin a new relationship -- served as a wake-up call for his wife.
"[My wife] saw the changes that it made in [my daughter]," he said. "She went from kind of an unhappy situation in her marriage to a situation now where her life was beginning to come back to the way life should be. With some fullness, and some meaning, and some happiness. And that sort of thing. And I think it kind of was a catalyst that gave her the momentum to say, 'A change needs to be made, and I think is a change that we need to make.'"
Trimble's ex-wife did not want to be interviewed by "Good Morning America," but did confirm that Trimble's account of their relationship and divorce is accurate.
The phenomenon of divorce -- or other issues -- spreading in social groups is not uncommon, according to Fowler's research.
"Your friends influence you, your siblings influence you, even your co-workers influence you," said Fowler, the co-author of "Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives."
For more than 10 years, Fowler and his colleagues have used research from the Framingham Heart Study to examine the scope of that influence. He said his research has demonstrated that problems such as smoking, drinking, even gaining weight can all be spread through a group.
"What these social network studies show, is that you can't do it alone," he said. "If you want to make a positive change in your own life, you have to get your friends and family involved. If you want to lose weight, you have to get your friends to lose weight. If you want to have a healthy marriage, you have to get your friends to have healthy marriages. We're really all in this together."
More Divorce in Trimble Family
Trimble said he believes his family is a strong example of the type of phenomenon Fowler's research outlines. His youngest daughter, Courtney Maples, is now also getting divorced.
"I think that same contagious thing that transferred from Alycia and her situation to my former spouse and me, transferred right on down the line to Courtney and her spouse," he said.
While Maples said she and her husband had been having troubles in their marriage previously, she said it was only after seeing her mother and sister get divorced that she contemplated one herself.
"When you have somebody very close to you go through a situation in their lives -- good or bad -- for a lot of us, it always brings out a time of self-reflection," Maples said. "My sister's my best friend. So to know that she made it through definitely helped me realize that it wasn't something I couldn't handle."
Terry Real appeared on "Good Morning America" today to discuss the idea of contagious divorce, and he offered some tips for what couples can do if they feel their relationship has been threatened by the divorce of a friend or family member.
Talk About It. Don't hold your fears in. Talk to your spouse about your insecurity.
Ask For Reassurance. Simply and directly tell your partner you're nervous and ask for his or her support.
Seize the Opportunity and Evaluate. Instead of running from the threat you may feel at this moment, take stock of your relationship. What's working well? What isn't? What are your relationship's strengths and weaknesses? Now is the time to take out whatever you've swept under the rug and take a good honest look .
Seize the Opportunity and Take Action. Talk to your partner about how the two of you might make the relationship work better. Perhaps the issue you've been neglecting is sex, or parenting as a team, or help with your in-laws. Use this shake-up as an opportunity to commit to strengthening your relationship by dealing with weak or conflicting areas that you've been shy to address.
Know When to Get Help. It may be that you have backed away from facing an issue because you've tried over and over again and gotten nowhere. That's generally an indication that you need help. Don't be shy about reaching out to a trained professional to unblock the channel of communication.