Even in adulthood, siblings can have a love-hate relationship that can drive any parent crazy. The bond is challenging and complicated even when siblings are grown up. The good news is that a positive relationship with adult siblings can be beneficial to a person's well-being. A study published in "Canadian Journal of Aging" found that the interactions between older siblings who had positive relationships decreased feelings of loneliness, provided emotional support and validation of earlier life experiences, and built feelings of closeness and sibling solidarity. As a parent, there are steps you can take to help your children end the fighting and build a positive relationship.

Create opportunities for your adult children to communicate in a healthy and appropriate manner. If possible, schedule a monthly family meeting during which your children can talk out disagreements. Establish norms that ensure that all communication during the family meeting will be objective and positive. While acting as facilitator in these meetings, allow all of your children equal time to share.

Spend time with each of your adult children individually. Jealousy and the impression that parents prefer the other sibling are often the root cause of sibling rivalry. "One of the most precious resources that siblings fight about is their parents' love and approval. If parents show favoritism toward a child, they can harm and even destroy sibling relationships," says Jeremy Boyle, a research associate at Brigham Young University.

Avoid taking sides when your children are fighting. Even if one of your children is clearly wrong, siding with the other person will only lead to defensiveness and even more resentment. Avoid being drawn into their problems or into listening to their complaints about each other. Explain that as a parent who loves them both, you will remain neutral no matter who is right or wrong.

Teach your children healthy conflict-resolution skills. Encourage communication using "I" rather than "you" statements. Emphasize that although they grew up together, they each have their unique personalities, perspectives and preferences. If it doesn't seem they will ever see eye-to-eye when it comes to certain issues, have them make a pact that they won't bring up those subjects in family gatherings.