Whether mom's golden child or her black sheep, siblings who sense that their mother consistently favors or rejects one child over others are more likely to show depressive symptoms as middle-aged adults, finds a new study by Cornell gerontologist Karl Pillemer.

Prior research has shown that parental favoritism among siblings negatively affects mental health and often triggers behavioral problems in children, teens and young adults, but the survey of 275 Boston-area families, co-directed by Purdue sociologist Jill Suitor, is the first to show that such harmful effects persist long into adulthood.

"Perceived favoritism from one's mother still matters to a child's psychological well-being, even if they have been living for years outside the parental home and have started families of their own," said Pillemer, the Hazel E. Reed Professor in the Department of Human Development and associate dean for extension and outreach in the College of Human Ecology, about his paper in the Journal of Marriage and Family (April 2010).

"It doesn't matter whether you are the chosen child or not, the perception of unequal treatment has damaging effects for all siblings," he added. "The less favored kids may have ill will toward their mother or preferred sibling, and being the favored child brings resentment from one's siblings and the added weight of greater parental expectations."

Favoritism may be difficult for mothers to avoid, however, as the researchers found that 70 percent of moms surveyed named a child to whom they felt closest and only 15 percent of children saw equal treatment by their mothers. Similarly, 92 percent of children and 73 percent of mothers specified a child with whom the mother battled most frequently.

The study, which controlled for family size, race and other factors, drew on interviews with 275 mothers in their 60s and 70s with at least two living adult children and also surveys of 671 offspring of the women. In addition to questions about emotional closeness or excessive conflict with a particular child, mothers and children were asked about the mother's expectations for who will care for her when she becomes ill or disabled. When mothers designated a child as her caregiver, all children suffered greater depressive symptoms, though the children's perceptions of their mother's preference did not relate to their mental health.

The findings could lead to new therapies for practitioners who work with later-life families, Pillemer said. "We have a powerful norm in our society that parents should treat kids equally, so favoritism can be something of a taboo topic. If counselors can help older parents and adult children bring some of these issues into the open, it may help prevent family conflict from arising."

In addition to Suitor, other co-authors include Charles Henderson, senior research associate in human development, and Ph.D. student Seth Pardo, both of Cornell.