When two parents of a previous marriage decide to join together as husband and wife, not only do they bring their children into the household, they also bring a lot of emotional baggage as well.

When I began researching the concept of family happiness, over 25 percent of the people who responded had come from homes where two families were joined together. These families shared a lot of joy in these households, and the majority felt they were, in fact, happy.

But there was also a lot of strain too—especially the homes in which the re-marriages were relatively new. It can be hard to adjust to all the changes that happen in a step-home, but it can be done and everyone can come up a winner.

Here are some of the common problems that happy stepfamilies have battled along the way, and some of the solutions that keep the peace.

The Problem: Hurt and angry feelings.
Usually when a stepfamily is formed, there’s another broken relationship left behind. It’s difficult for children to sort out allegiances in these situations. Strong emotional attachments to stepparents or stepsiblings don’t happen overnight, nor should they. Often, a stepparent will be blamed for the divorce of a biological parent or the disruption of a cohesive single-parent family by the introduction of a "needy" adult and "pesky" children.

The Solution: Allow time for adjustment. Give the children a listening ear, and don’t tell them how they "should" feel. Validate their feelings—tell them you understand that it must be difficult to be in a situation where adults are making a lot of choices that affect them.

The Problem: Differences in discipline styles between stepparents.
Even natural parents differ in how to care for children; if you think about it, that’s probably one of the reasons that the two parents ended up splitting in the first place. So don’t be surprised if two adults who remarry have two different takes on child rearing. A main problem in the blended family is that the lines of authority are not so clear—can and should the stepparent assume the same role as the parent when it comes to limit-setting and punishments? Kids have a sixth-sense about this issue, and can get adults battling it out in no time!

The Solution: Remember the adage that all adults (teachers, coaches, ministers) must be treated with respect. There’s no excuse for dismissing the concerns of an adult who cares for you, biological parent or not! Adults should establish clear expectations about what’s allowed, and prohibited, in the household. They may need to do that negotiating in private. Next, sit with your new family and set some guidelines—in writing, if need be—about the rules and the lines of command in the household. Kids have to know that you and your new spouse present a unified front.

The Problem: The "outside" parent is causing problems.
It can be very disruptive to a family when the parent who is not living in the new home appears to interfere with the formation of a new stepfamily. One family I treat is raising two stepsister, each six-years-old. The bio-father of the daughter takes her out to movies, amusement parks or to have special treats and leaves the stepsister behind crying her eyes out. That causes a lot of pain in the family.

The Solution: You can’t control the behavior of others, particularly after you split with them. Moreover, when possible, children should be able to spend abundant time with their parents. It’s important to never put your child’s other parent down, and also foster a close relationship between the two. If you can resist judging your ex-partner harshly, there will be more room for negotiation over time. As long as the bio-parent of your child is providing sufficient safety, you have to accept that he or she doesn’t follow the same rules you do in your home. And, like it or not, the other members of your home must accept it too!

Growing together as a stepfamily requires time, patience and good skills at juggling everybody’s needs. It’s not always easy (in fact, it rarely is), but putting effort into forming a new family unit pays dividends over the rest of your life, and the life of your children.

Scott Haltzman, MD is a clinical assistant professor at Brown University Department of Psychiatry and Human Behavior. Dr. Haltzman is also the author of "The Secrets of Happy Families: Eight keys to building a lifetime of connection and contentment," "The Secrets of Happily Married Men: Eight Ways to Win Your Wife's Heart Forever," and "The Secrets of Happily Married Women: How to get more out of your relationship by doing less." You can get more information at his website, www.drscott.com.