Any family relationship is complex, but in-law relationships are particularly difficult because they have the obligations and expectations of family without the benefits of intimacy, comfort, and support. This is especially true when the relationships are new. In-laws do not know each other's personality quirks and passions. They have little idea which buttons they can push, what happens when they push one, and which buttons the new person will push in them. They have not survived disagreements and arguments. In-laws do not share a common history. They are virtual strangers.

The expectation that these strangers will immediately become loving members of our clans is unrealistic. It takes years to merge a newcomer into the family. Many misunderstandings may be suffered before in-laws can trust that they can truly work together, and many never do. On the positive side, in-laws also lack the "baggage" that comes from years of less-than-positive family interactions. That can make the new in-law easier to deal with than one's own offspring or one's own parents.
Nonetheless, from the very beginning, in-laws are expected to be present at events only open to family. Or in-laws may be imposed upon for favors or commitments usually reserved for close friends. Sometimes they are asked for financial or personal sacrifices greater than they would request from their closest friends. Either generation might resent these requests from someone related by neither blood nor choice.

We become an in-law by a decision made by someone else. The younger generation makes the choice of partner, but they have no say in all the relatives who come along with their mate. The older generation often has no input. Both generations feel resentful that they are saddled with relations and obligations they did not choose. Those who wish to control their own fates are frustrated. Parents assumed their child would marry someone from their own socioeconomic, cultural, national, or religious group, but the child chooses differently. Or the parents assume their child would marry a perfect superstar, but instead he or she marries a mere mortal. In short, the reality does not measure up to the parents' fantasy.

The in-law child, too, faces disappointment. Some have barely met the in-laws before they find themselves enmeshed in their spouse's family. The new family differs in ways large and small. One family maybe closer, the other more distant. The new in-law family may have all the friction of one's own family plus some new and unfamiliar problems. How easy it is for everyone to be disappointed.

Other times, parents are thrilled at first and disappointed later. The disillusionment can come for any number of reasons. Perhaps the parents had hoped they would be included in the lives of their grandchildren and they are not. Or perhaps siblings are asked to babysit more than they want. Sometimes parents become irate at the in-law child because they cannot protect their own children from mistakes and so they fault the in-law child. Parents often blame the in-law because it is too painful to admit that their own children and grandchildren are just as imperfect as their own families. In brief, they have their own version of ideal, and they blame the in-law for the imperfections that are part of life.

In-law children may have expected no relationship with the parents of their new spouse and discover that they are embedded in a whole circle they did not bargain for. They may be expected to help out their spouse's parents and siblings on the weekend or socialize with family, when they don't have time for their own friends and family. Or they may have expected the in-laws to fill in all the holes their parents left and they do not. They may have wanted the perfect parents who are all-forgiving and who give money and time generously, only to find their in-laws are just as flawed as their own parents. The parents-in-law may be completely involved in their own lives and have little time or interest in getting to know the new family member. Both generations must cope with the imperfect.

Excerpted from Ruth Nemzoff's new book, Don't Roll Your Eyes: Making In-Laws Into Family(Palgrave/Macmillan, September 2012)