The basis of family connection is no longer attributed to "blood" but to the emotional bonds that evolve in the context of humans' needs for care, companionship and continuity with close relatives. Some evolutionary psychologists argue that grandmothers played a key role in the development of early human societies. In ancient societies, there is evidence for a "grandmother effect" whereby mothers who had a mother still living, were more likely to see their own children survive to adulthood. When grandmothers lived long enough to care for their children's children, they provided an extra pair of hands for child care and food gathering, and passed on their accumulated parenting experience.
In modern times, the grandmother effect translates into continued emotional and practical support. Grandmothers now are a staple in the portfolio of child-care provision across all classes, across all ethnic groups. Grandparents Association reports that in the United Kingdom, 60 percent of child-care provision is provided by grandparents, and one in every hundred children is living with a grandparent. School records throughout Britain show that a grandparent is, in a majority of cases, the person listed as the back-up contact if the parents are not available. This suggests that parents recognize and depend upon grandparents as a reliable source of care.
From children's perspective, too, grandparents are common sources of support; children often say they find it easy to confide in grandparents, and identify them as key members of their family. The emotional closeness and stability grandparents provide, particularly during times of family stress (such as divorce), has been shown to facilitate children's emotional adjustment. The increase in divorce rate over the past sixty years is often seen as evidence that the family as a whole is in decline, but the bonds between grandparent, parent and child remain strong, and endure as a key social and emotional structure.
These important connections between grandparent and grandchild, however, often depend on good relationships between the parents and grandparents. Mothers remain the gatekeeper to their children, and maternal grandparents are far more likely to have close and regular contact with their grandchildren than paternal grandparents. For paternal grandparents, key to continuing closeness to a grandchild is a good relationship with a daughter-in-law. Yet, according to my study of in-law relationships, mother-in-law and daughter-in-law relationships are often described as "uncomfortable", "tense", "uneasy", and each is likely to describe the other as "difficult", "unwelcoming" or "hostile". In my study of 49 couples and their in-laws, 60% of the mothers-in-law and daughters-in-law said that they experienced disappointment or frustration with one another. In our culture, this tension is the subject of distasteful jokes, but the subject matter is deadly serious, and impacts on all members of the family.
In-law tension is common across cultures, and may be universal. Steven Pinker wryly notes that from an evolutionary point of view, it comes as no surprise that in-laws rate among the three major causes of marital strife - infidelity and stepchildren being the second and third sources. Someone who is close to you, with influence over your genetic offspring but not themselves genetically linked to you, will be carefully, suspiciously observed.
Marriage in some form is a feature of all known societies, and involves the paradox that marriage is both necessary to the continuation of the family, and threatens family solidarity by introducing strangers into its midst. From parents' point of view, a child's marriage displaces them as next of kin, with primary influence over a child's well being. From the perspective of a new spouse, marriage marks the start of her own family, and her aim is usually to limit others' influence. Daughter-in-law and mother-in-law tend to monitor their status and influence relative to one another far more carefully than the men. Domestic matters, such as housework, mealtimes and menus, retain symbolic meaning to women in the family: even women who are proud to have too much to do to maintain a perfectly tidy and dust-free house, may feel profoundly criticised by a mother-in-law's quizzical appraisal of untended laundry and a muddy floor.
When children are born to the couple, the question may arise as to whose experience and values provide the final authority. Different attiudes towards child-care can lead to new battles about status and control. In-law conflict is likely to spread into marital conflict, as a wife says to her husband, "Why aren't you supporting me?" In-law conflict can breach mother/son relations as a husband says to his mother, "Why aren't you respecting my wife's maternal authority?"
Some conflicts signal generational shifts in child-raising norms, particularly those involving a woman's balance between child care and career. How can a grandmother stand respectfully aside when she thinks the mother of her grandchildren is not the best possible parent? "The best thing for my grandchildren is for their mother to stay at home with them," says Chloe, Denise's mother-in-law. "I know that's not fashionable. I know that's not Denise. But that's what I want." Denise's mother, Alicia, is also concerned at her daughter's workload. Alicia shares many of Chloe's views about child care and family stress; but nonetheless, for Alicia, her daughter comes first, and she gives priority to Denise needs, while Chloe's priority is with her own blood family.
Negotiating the trips and switches of overlapping families so that parents and grandparents alike can maintain those precious bonds is an essential skill, because so much is at stake. The balance between a grandmother's emotional involvement and the modern assumption that a mother has primary control is difficult to achieve, but the cost of failure is high. I observed a gamut of unnecessary suffering-from the daughter-in-law who says, "My mother-in-law has made my life a misery. She tries to control everything I do because I'm the mother of her grandson," to the mother-in-law who asks, "What have I done to deserve this ban against seeing my grandchildren. Look at me! Do you see the evil woman my daughter-in-law sees? The one who isn't fit to have contact with the boys who matter more to her than anything in the world? How can she break my heart like this?" Such suffering lays waste to the possible benefits to children of contact with grandparents, and the emotional and practical contributions that grandparents might make to the entire family.
When we acknowledge and understand common patterns of in-law conflict, we shall be better placed to negotiate these complex alliances and make good use of the invaluable bonds of the extended family.